Merge pull request #1 from tobias-engelmann/darkside

Merged darkside into master
calendar nearly finished - permission share broken
fixed issue with series appointments
fixed issue with calendar share form
series / appointments improved
fixed error in appointments view
fixed error in appointments view
fixed error in appointments view
added series and appointment forms
Merge branch 'devel-backend' of github.com:tobias-engelmann/ProjectCM into devel-backend
various changes and fixes
various changes and fixes
various changes and fixes
various changes and fixes
various changes and fixes
various changes and fixes
various changes and fixes
calendar functionality finished
various changes and fixes
various changes and fixes