Commit the start of PimTextEdit. This library will provide a text edit with PIM features like signature support, quote highlighting and inline images, and also Steve's rich text builders.

Replaces part of KMeditor and KMComposerEditor.

This is very much WIP, it compiles and links, but that's it.
I just commit because I want to go to bed now.
Will be finished during the next week(s)

Please check if I got the KMime/KPimIdentities dependencies correct,
especially the target_link_libraries.

svn path=/trunk/KDE/kdepimlibs/; revision=934840