Added help_text for Issue #59 to help user avoid bug
Send the node/content data when repositioning

This allows the UI to update based on new data after the move. For
example, widgets can change their `display_name`s based on their tree
position.
Merge remote-tracking branch 'zmetcalf/issue#59-tabs-with-same-title'

Conflicts:
	widgy/contrib/page_builder/models.py