Merge pull request #1 from itedd/master

Update from master repo
Merge pull request #23 from synopia/master

Tickets #5 and #12
Merge pull request #2 from itedd/master

merge from master
merged arBmind/itedd master
Einige Korrekturen
Merge branch 'master' of https://github.com/MartinKoerner/itedd
#12 Events als Liste (embeddable) - Liste verschönert und von session auf get parameter umgestellt
Merge pull request #24 from MartinKoerner/master

Korrekturen an der Readme
#12 Events als Liste (embeddable) - fixed broken junit test
Merge pull request #25 from thobach/issue-12

Issue 12
removed Admin and Organizer class
separated User from UserGroup
each user may administrate several UserGroups