merge SVN commit 1101811 by winterz:

keep track of the incidence sequence number and only show alarms
where the sequence number is >= then the value we are tracking.
this should help us not show outdated alarms, like when someone
edits an alarm while the current one is showing.

svn path=/tags/kdepim/enterprise35.0.20100305.1099257/kdepim/; revision=1101812