initialize v0.5 branch and add best practices checking gem
redo Gemfiles and updates thin, letter-opener, fog, faker and carrierwave gems
Update Bootstrap 2.1.0 => 2.2.1.2
Adds maintenance mode gem. To be completed by the definition of a custom maintenance page
add rails-indexes gem
add missing indexes and remove rails_indexes gem (not smart enough)
fixes a few best practices warnings
fixes best practices warning. Still missing unused methods and instance variables occurences in controller
- simplify artist controller with the usage of responder : to be tested!!

- correct a few best practices warnings
Add missing foreign keys & make all tables trackable
- Improve factories

- Correct tests
- make music_labels and approvals trackable
improve albums list with nice but basic display
merge from master
Remove useless "user_is..?" helpers. It is replaced with a "can_debug?" and user_is_admin? that is very specific to the admin role.

Check why artist popup test does not pass anymore.
Enables gzip compression on Heroku
disables rails static asset server to rely on heroku's one on production
add debug mode management as a cached volatile value. begin implementation of screen to manage it. To be continued
fixes music_labels tests (weird foreign key violation error inside factories
move test users creation in a single re-playable task
reads YAML files for import feature