Merge pull request #97 from cavarelli/rebase_develop

Rebase develop
Header of backoffice incorporate link to voxe.org and changed root of backoffice
Better javascript code for select2
Possibility to chooose the propositions by a high level tag in the backoffice candidate
Possible to access to this functionnality with /backoffice/propositions, select the first high tag level by default
Improvement of the function
When on /propositions, it shows all the propositions and when a categorie is selected (/propositions/categorie/:name), it show the propositions of the categorie
New functionnality and slight redisgn of candidacy's profile
Modification of the candidacy's profile page and of the javascript for link testing
clean controller code