#221 Default window style interfere with resizer window (thanx to Magnus Lindhe)

#224 Reverted Fixed a bug that freezed when changing DocumentPane Orientation (thanx to sukamoni)
See pull request for issues with this PR

#240 NullReferenceException in LayoutDocumentControl.OnModelChanged (thanx to Khaos66)

#225 Keyboard up/down in textbox in floating anchorable focusing DropDownControlArea (thanx to Muhahe LyonJack bdachev)

#229 Ensure DocumentPaneGroup (fix crash when documentpane on layoutGroup) (thanx to sukamoni)