Merge pull request #62 from adoulrac/arthur/gestion_groupes

Add group, delete group, delete user OK.
Merge pull request #65 from adoulrac/rachid/release2

Bug fix about pictures requests
Bug fix about pictures requests
Picture controlelr code review
Merge pull request #66 from adoulrac/rachid/release2

Picture controlelr code review
Synchro. with DATA
Merge pull request #67 from adoulrac/selim/picturesDisplay

Synchro. with DATA
Bug fix in stub
Merge pull request #68 from adoulrac/selim/release2

Bug fix in stub
Bug fix about data receiver instance
Merge pull request #69 from adoulrac/rachid/release2

Bug fix about data receiver instance
Conflict solved.