diff --git a/Makefile b/Makefile
index 62cb3a2f..bc945962 100644
--- a/Makefile
+++ b/Makefile
@@ -1,210 +1,210 @@
 # Makefile for Sphinx documentation
 #
 
 # You can set these variables from the command line.
 SPHINXOPTS    =
 SPHINXBUILD   = sphinx-build
 PAPER         =
 BUILDDIR      = build
 SPHINXINTL    = sphinx-intl
 INTL_LOCALES  = -l de -l fr -l zh_CN
 # Internal variables.
 PAPEROPT_a4     = -D latex_paper_size=a4
 PAPEROPT_letter = -D latex_paper_size=letter
 ALLSPHINXOPTS   = -d $(BUILDDIR)/doctrees $(PAPEROPT_$(PAPER)) $(SPHINXOPTS) source
 # the i18n builder cannot share the environment and doctrees with the others
 I18NSPHINXOPTS  = $(PAPEROPT_$(PAPER)) $(SPHINXOPTS) source
 HELPDOCS_LOCALES = de_DE:de fr_FR:fr zh_CN:zh_CN
 
 .PHONY: help clean html dirhtml singlehtml pickle json htmlhelp qthelp devhelp epub latex latexpdf text man changes linkcheck doctest gettext
 
 help:
 	@echo "Please use \`make <target>' where <target> is one of"
 	@echo "  html       to make standalone HTML files"
 	@echo "  dirhtml    to make HTML files named index.html in directories"
 	@echo "  singlehtml to make a single large HTML file"
 	@echo "  pickle     to make pickle files"
 	@echo "  json       to make JSON files"
 	@echo "  htmlhelp   to make HTML files and a HTML help project"
 	@echo "  qthelp     to make HTML files and a qthelp project"
 	@echo "  devhelp    to make HTML files and a Devhelp project"
 	@echo "  epub       to make an epub"
 	@echo "  latex      to make LaTeX files, you can set PAPER=a4 or PAPER=letter"
 	@echo "  latexpdf   to make LaTeX files and run them through pdflatex"
 	@echo "  text       to make text files"
 	@echo "  man        to make manual pages"
 	@echo "  texinfo    to make Texinfo files"
 	@echo "  info       to make Texinfo files and run them through makeinfo"
 	@echo "  gettext    to make PO message catalogs"
 	@echo "  changes    to make an overview of all changed/added/deprecated items"
 	@echo "  linkcheck  to check all external links for integrity"
 	@echo "  doctest    to run all doctests embedded in the documentation (if enabled)"
 
 submodules:
 	@if [ ! -d "source/webmail-user-guide/roundcubemail/.git" -o ! -f "ext/kolab/fancyfigure/__init__.py" -o ! -d "source/webmail-user-guide/roundcubemail-plugins-kolab/.git" ]; then \
 		if [ -x "$$(which git 2>/dev/null)" ]; then \
 			git submodule init ; \
 			git submodule update ; \
 		fi ; \
 	fi
 	for plugin in $$(find source/webmail-user-guide/roundcubemail-plugins-kolab/plugins/ -type d -name "en_US"); do \
 		plugin=$$(echo $${plugin} | \
 				sed \
 					-e 's|source/webmail-user-guide/roundcubemail-plugins-kolab/plugins/||g' \
 					-e 's|/helpdocs/en_US||g' \
 			) ; \
-		ln -sfv ../../../roundcubemail-plugins-kolab/plugins/$${plugin}/helpdocs/en_US/ source/webmail-user-guide/roundcubemail/en_US/_plugins/$${plugin} ; \
+		ln -sfv ../../../roundcubemail-plugins-kolab/plugins/$${plugin}/helpdocs/en_US/ source/webmail-user-guide/roundcubemail/en_US/_plugins/$${plugin} || : ; \
 	done
 
 helplocales:
 	@for langmap in $(HELPDOCS_LOCALES); do \
 		lang=$${langmap:0:5} ; \
 		destlang=$${langmap#*:} ; \
 		echo $$lang "=>" $$destlang ; \
 		if [ -d "locale/$$destlang" ]; then \
 			mkdir -p locale/$$destlang/LC_MESSAGES/webmail-user-guide/roundcubemail ; \
 			ln -sf ../../../../../source/webmail-user-guide/roundcubemail/locale/$$lang/LC_MESSAGES locale/$$destlang/LC_MESSAGES/webmail-user-guide/roundcubemail/en_US ; \
 		fi ; \
 		for docs in $$(find source/webmail-user-guide/roundcubemail-plugins-kolab -type d -name "helpdocs"); do \
 			if [ -d "locale/$$destlang/LC_MESSAGES/webmail-user-guide/roundcubemail/en_US" ]; then \
 				plugin=$$(basename $$(dirname $$docs)) ; \
 				mkdir -p locale/$$destlang/LC_MESSAGES/webmail-user-guide/roundcubemail/en_US/_plugins ; \
 				ln -sf $$(pwd)/$$docs/locale/$$lang/LC_MESSAGES locale/$$destlang/LC_MESSAGES/webmail-user-guide/roundcubemail/en_US/_plugins/$$plugin ; \
 			fi ; \
 		done ; \
 	done
 
 helpdocs: submodules
 	@cd source/webmail-user-guide/roundcubemail/en_US/_plugins/ ; \
 	for docs in $$(find ../../../roundcubemail-plugins-kolab/ -type d -name "helpdocs"); do \
 		plugin=$$(basename $$(dirname $$docs)) ; \
 		ln -sf $$docs/en_US/ $$plugin ; \
 	done
 
 locales: gettext helplocales
 
 clean:
 	@rm -rf $(BUILDDIR)/*
 	@rm -rf source/webmail-user-guide/roundcubemail/
 	@rm -rf source/webmail-user-guide/roundcubemail-plugins-kolab/
 	@rm -rf source/*/_fancyfigures/
 	@rm -rf locale/*/LC_MESSAGES/webmail-user-guide/roundcubemail
 
 html: submodules
 	$(SPHINXBUILD) -b html $(ALLSPHINXOPTS) $(BUILDDIR)/html
 	@echo
 	@echo "Build finished. The HTML pages are in $(BUILDDIR)/html."
 
 dirhtml: clean
 	$(SPHINXBUILD) -b dirhtml $(ALLSPHINXOPTS) $(BUILDDIR)/dirhtml
 	@echo
 	@echo "Build finished. The HTML pages are in $(BUILDDIR)/dirhtml."
 
 singlehtml: clean
 	$(SPHINXBUILD) -b singlehtml $(ALLSPHINXOPTS) $(BUILDDIR)/singlehtml
 	@echo
 	@echo "Build finished. The HTML page is in $(BUILDDIR)/singlehtml."
 
 pickle: clean
 	$(SPHINXBUILD) -b pickle $(ALLSPHINXOPTS) $(BUILDDIR)/pickle
 	@echo
 	@echo "Build finished; now you can process the pickle files."
 
 json: clean
 	$(SPHINXBUILD) -b json $(ALLSPHINXOPTS) $(BUILDDIR)/json
 	@echo
 	@echo "Build finished; now you can process the JSON files."
 
 htmlhelp: clean
 	$(SPHINXBUILD) -b htmlhelp $(ALLSPHINXOPTS) $(BUILDDIR)/htmlhelp
 	@echo
 	@echo "Build finished; now you can run HTML Help Workshop with the" \
 	      ".hhp project file in $(BUILDDIR)/htmlhelp."
 
 qthelp: clean
 	$(SPHINXBUILD) -b qthelp $(ALLSPHINXOPTS) $(BUILDDIR)/qthelp
 	@echo
 	@echo "Build finished; now you can run "qcollectiongenerator" with the" \
 	      ".qhcp project file in $(BUILDDIR)/qthelp, like this:"
 	@echo "# qcollectiongenerator $(BUILDDIR)/qthelp/KolabGroupware.qhcp"
 	@echo "To view the help file:"
 	@echo "# assistant -collectionFile $(BUILDDIR)/qthelp/KolabGroupware.qhc"
 
 devhelp: clean
 	$(SPHINXBUILD) -b devhelp $(ALLSPHINXOPTS) $(BUILDDIR)/devhelp
 	@echo
 	@echo "Build finished."
 	@echo "To view the help file:"
 	@echo "# mkdir -p $$HOME/.local/share/devhelp/KolabGroupware"
 	@echo "# ln -s $(BUILDDIR)/devhelp $$HOME/.local/share/devhelp/KolabGroupware"
 	@echo "# devhelp"
 
 epub: clean
 	$(SPHINXBUILD) -b epub $(ALLSPHINXOPTS) $(BUILDDIR)/epub
 	@echo
 	@echo "Build finished. The epub file is in $(BUILDDIR)/epub."
 
 latex: clean
 	$(SPHINXBUILD) -b latex $(ALLSPHINXOPTS) $(BUILDDIR)/latex
 	@echo
 	@echo "Build finished; the LaTeX files are in $(BUILDDIR)/latex."
 	@echo "Run \`make' in that directory to run these through (pdf)latex" \
 	      "(use \`make latexpdf' here to do that automatically)."
 
 latexpdf: clean
 	$(SPHINXBUILD) -b latex $(ALLSPHINXOPTS) $(BUILDDIR)/latex
 	@echo "Running LaTeX files through pdflatex..."
 	$(MAKE) -C $(BUILDDIR)/latex all-pdf
 	@echo "pdflatex finished; the PDF files are in $(BUILDDIR)/latex."
 
 text: clean
 	$(SPHINXBUILD) -b text $(ALLSPHINXOPTS) $(BUILDDIR)/text
 	@echo
 	@echo "Build finished. The text files are in $(BUILDDIR)/text."
 
 man: clean
 	$(SPHINXBUILD) -b man $(ALLSPHINXOPTS) $(BUILDDIR)/man
 	@echo
 	@echo "Build finished. The manual pages are in $(BUILDDIR)/man."
 
 texinfo: clean
 	$(SPHINXBUILD) -b texinfo $(ALLSPHINXOPTS) $(BUILDDIR)/texinfo
 	@echo
 	@echo "Build finished. The Texinfo files are in $(BUILDDIR)/texinfo."
 	@echo "Run \`make' in that directory to run these through makeinfo" \
 	      "(use \`make info' here to do that automatically)."
 
 info: clean
 	$(SPHINXBUILD) -b texinfo $(ALLSPHINXOPTS) $(BUILDDIR)/texinfo
 	@echo "Running Texinfo files through makeinfo..."
 	make -C $(BUILDDIR)/texinfo info
 	@echo "makeinfo finished; the Info files are in $(BUILDDIR)/texinfo."
 
 gettext: clean submodules
 	$(SPHINXBUILD) -b gettext $(I18NSPHINXOPTS) $(BUILDDIR)/locale
 	$(SPHINXINTL) update -p $(BUILDDIR)/locale -d locale $(INTL_LOCALES)
 	@echo
 	@echo "Build finished. The message catalogs are in $(BUILDDIR)/locale."
 	rm -rf locale/*/LC_MESSAGES/webmail-user-guide/roundcubemail
 
 update-txconfig-resources: gettext
 	rm -rf $(BUILDDIR)/locale/webmail-user-guide
 	$(SPHINXINTL) update-txconfig-resources --transifex-project-name kolab-documentation -p $(BUILDDIR)/locale -d locale
 	@echo
 	@echo "Transifex resources have been updated."
 
 changes: clean
 	$(SPHINXBUILD) -b changes $(ALLSPHINXOPTS) $(BUILDDIR)/changes
 	@echo
 	@echo "The overview file is in $(BUILDDIR)/changes."
 
 linkcheck: clean
 	$(SPHINXBUILD) -b linkcheck $(ALLSPHINXOPTS) $(BUILDDIR)/linkcheck
 	@echo
 	@echo "Link check complete; look for any errors in the above output " \
 	      "or in $(BUILDDIR)/linkcheck/output.txt."
 
 doctest: clean
 	$(SPHINXBUILD) -b doctest $(ALLSPHINXOPTS) $(BUILDDIR)/doctest
 	@echo "Testing of doctests in the sources finished, look at the " \
 	      "results in $(BUILDDIR)/doctest/output.txt."