Constraints Api's
Small bug fixes and cleanup
Merge pull request #256 from gaethofs/master

'Gewone' kalender
Merge branch 'master' of https://github.com/CalZoneVUB/CalZone into TimFrondEnd
API not frozen list
Fix
Frozen trajecten
Merge branch 'master' of https://github.com/CalZoneVUB/CalZone

# By Timbo925
# Via Timbo925 (2) and Christophe Gaethofs (1)
* 'master' of https://github.com/CalZoneVUB/CalZone:
  Frozen trajecten
  Fix
  API not frozen list
  Small bug fixes and cleanup
  Constraints Api's