Adds var isVisible in ResourceNode
Updates ResourceNode properties form
Refactoring workspace creation.
Merge pull request #891 from ngodfraind/master

Fixing a bug happening when importing a csv with no user role.
Merge branch 'master' of https://github.com/claroline/CoreBundle into bugfixes
Allows visibility mode to be switched in resources manager
Adds visibility button info translations
Merge branch 'master' of https://github.com/claroline/CoreBundle into resource-visible-option
Merge pull request #892 from kitan1982/resource-visible-option

!!! NEW MIGRATIONS!!! Resource visible option
Importers can add content to an existing workspace.
Merge pull request #893 from ngodfraind/bugfixes

Bugfixes
Adds drag'n drop to reorder desktop tools
Merge branch 'master' of https://github.com/claroline/CoreBundle into drag-and-drop-desktop-tools
Merge pull request #894 from kitan1982/drag-and-drop-desktop-tools

Drag and drop desktop tools
Fixes bug with links in workspace model
Merge pull request #895 from kitan1982/workspace-model-bugfix

Fixes bug with links in workspace model
Fixes see-hidden-files button in resource manager when refreshing
Merge pull request #896 from kitan1982/resource-visible-bugfix

Fixes see-hidden-files button in resource manager when refreshing
messages "to" field size increased to 16000 characters
Merge pull request #897 from ngodfraind/bugfixes

messages "to" field size increased to 16000 characters