Merge pull request #126 from hpi-swt2/dev

merge dev into Dolphins
added first version of calendar
fixed css problem
Merge pull request #136 from hpi-swt2/dev

Dev
removed calendar rendering on events side
merged from fork svenlehmann
Merge branch 'dev' into d/feature/#114

Conflicts:
	Gemfile
	Gemfile.lock
	app/assets/javascripts/application.js
	app/views/events/_calendar.html.erb
fixed conflicts, remove require application js form application.html, due to multiple requiring
only show events, which are created by current_user & mark non-approved events red
merge
merge
merged calendar into dev