Replace Twitter Bootstrap by Zurb Foundation 4.0.

  + removed activeAdmin because it its not useful!
  + start layouting from scratch
  + new javascript engine: zepto instead of jquery (because it is
lightweight
Remove .rvmrc. Add Group model.
Enable localization
Add polymorphic tagging to groups.
Fix routing error for devise when no locale was set.
Create group scaffold.
Change database name to auditorium_next to prevent issues in case of database migrations.
Add groups form to create and edit groups data:
+ add group type chooser
+ add tokeninput fields with jquery tokeninput
+ user can search and create multiple tags on demand
Add translations to tokeninput javascript. But it does not respond instantly.
Changed style of token input fields.
Add creator to groups.
Add Question and Answer model as STI of Posts.
Add Announcement as STI post model.
Add comments polymorphic resource. Remove Active Admin.
Define color schema. Change hover color for topbar.
Change button styles. Add flash container for messages.
Removed unnecessary webfonts.
Split posts table into:

+ questions
+ answers
+ recordings
+ announcements

for easier maintanence.
Remove spec files to begin from scretch because tests were not maintained the last time...
Test group model.