Merge pull request #149 from leider/master

layout runderneuert :)
Merge pull request #150 from leider/master

Viel Layouting und persistente Session / Cookie
First shot for calendar in sidebar
refactoring
extracted activity validation
Calendar almost final

!!! Activity DB format changed !!! Drop the collection in mongo
color and text formatting and minor tweaks in calendar
now we have restart persistent sessions!
Merge pull request #152 from leider/Calendar

A real huge pull request with lots of stuff