Merge pull request #897 from ngodfraind/bugfixes

messages "to" field size increased to 16000 characters
Fixes display when creating resource
Merge branch 'master' of https://github.com/claroline/CoreBundle
Merge pull request #898 from kitan1982/master

Fixes display bug when creating resource
Merge pull request #899 from ngodfraind/bugfixes

Fixing the group import.
Removes user roles from group settings form
Merge pull request #900 from kitan1982/role-by-user-bugfix

Removes user roles from group settings form
Merge pull request #901 from ngodfraind/bugfixes

Add the file extensions when missing if dling an archive.
Merge pull request #902 from ngodfraind/bugfixes

Refactoring workspace role management GUI.
Merge pull request #903 from ngodfraind/bugfixes

Resource menu displayed only if the action is implemented.
Add uniqid to publicurl.