Removed category useless files and fix bug of no category message
Can link a workspace to a category
Updated workspace link page and workspaces list GUI
Update admin registration into workspace to handle workspace linked to category
Merge branch 'master' of https://github.com/claroline/CoreBundle into associate_workspace_to_category
Fixes GUI bug of workspace linked to incorrect category
layout update
Added accessibility date for resourceNode
Checked accessibility date in resource search
Initializes accessibility date with parent directory date
Refactors accessibleTo into accessibleUntil
Merge pull request #622 from kitan1982/associate_workspace_to_category

Associate workspace to category
Fixes incorrect migrations
Merge pull request #623 from kitan1982/validity_date_resource

Validity date resource (NEW MIGRATIONS)
Begins adding activity rules and evaluation
Merge pull request #627 from kitan1982/activity-refactoring

Activity refactoring
repository method fix
Added var for additional datas in Rule
Adds resource access date constraint for activity rule validator
Merge pull request #628 from kitan1982/activity-refactoring

Activity refactoring