Milestone kmess-1.5

With 1.5-pre2 out, the main focus of 1.5 is fixing any remaining bugs. Some features could still use some final polish.

Planned changes from 1.5pre2:

• Fix the balloons, use KDE passive popups instead: done.
• Fix annoying bugs users encounter: done.
• Implement "Get Hot New Stuff": postponed to 1.6.