- removed ticks from persistance
- removed Runs concept from model
- introduced RunInterval as summarized runs in a specific time interval
- using RunIntervals to store run information in a compact way
 - using 15 minutes as interval size as tradeoff between compactness and accuracy
- hand in missing pom.xml for commons project
- added toString() implementation to RunInterval
- removed scrollbars on run calendar agenda views
- improved run administration
- fixed bugs in run grouping for calendar view
- merged changes from tickRemoval branch