fixes 123. topic selection via radio buttons
Merge branch 'andrey'
Merge pull request #130 from stoewer/master

Figure remove figure name
Merge pull request #131 from asobolev/master

topic selection via radio buttons (fixes #123)

LGTM
Conference owners and admins can edit abstracts

Owners of a conference can update and delete abstracts
Admins can update and delete abstracts

Fixes #119
Conference creation restricted to admins
Admins can edit and delete conferences.