Fixed bug when not synchronizing children without changes
Stop execution for main object
Fixed specs
When forcing parent synchronize remove self api notified link
* Changed callbacks from create|update to save
* Allow to track if object is deleted in other system
* Updated force_parent_sync method, allowing to continue current task unless parent task isn't created
When parent sync info removed, remove child sync info also
Parent_attribute now works together with force_parent_sync
Rails 4.0 -> 4.1