Contents tree window: when region has only one content, when dragging content, it's impossible to return it back to it's position

[Audrunas]

Related to #1076

Open content tree panel Find a region with one content Start dragging content: it is impossible to put content back to it's region, because drop area doesn't show

The only way is to drop content in another region and then drag again back to start region

[Audrunas]

Even adding a new droppable area doesn't work :(

[Audrunas]

Fix wil be available from 1.9.0-beta3+

[daivabrazukaite]

Impossible to drag widget with region that has child widget also with regions to first level region. http://bettercmsdemo.devbstaging.com/1029-test/1103page/