Fix/workaround issue in Releaf::ContentNode::SinglenessValidator
Create releaf-permissions gem
Merge branch 'master' of https://github.com/cubesystems/releaf
Create releaf-content gem
Fix Releaf::COntentNode::SinglenessValidator when placing node under root

Add explanation of example
Add Releaf::ContentNode::RootValidator
Eliminate code duplication
Don't die with ActiveRecord::RecordInvlid when moving/copying nodes
Use &:method_name when appropriate
Small CotentController optimization
Remove @node from validators when validation is finished.

Otherwhise when looking at Node.validators one could get confused that
validation is tied to specific node, as it displays @node and last node
that was validated
Remove unused legacy code
Only show classes of valid node contents when creating new node
Move and copy content nodes in transaction
Remove code duplicate in ContnetControllers copy_dialog and move_dialog vies
Add Releaf::BaseController#render_notification method
Convert partial to unix file format
Add association prefix for nested resources "add" button
Refactor node copying and moving
Refactor node copying and moving