Metadata profile edit: Optimize Drag&Drop and metadata editing for hierarchy of metadata elements

[natasab]

Editing of a child metadata element to be top level element is at the moment almost not possible for users. It is not clear how to remove an element from the hierarchy and turn this element (along with its child elements) as a top level element.

[natasab]

See also feature request http://imeji.org/a-possibility-to-choodse-the-hierarchy-level-of/