[REFACTOR] moved the property testers into the ui package

This is Eclipse GUI logic and has nothing to do with Saros Business
Logic at all.

Change-Id: I6518874bd885f5f249032729c030cfe60564dfb4
Reviewed-on: http://saros-build.imp.fu-berlin.de/gerrit/1166
Tested-by: Jenkins CI
Reviewed-by: Stefan Rossbach <srossbach@arcor.de>