[WPF] Error when using nested TextEntry in Notebook sample in ScrollView.
[WPF] implement WebViewBackend.Title using script invoke
[MAC] fix url handling for OnNavigateToUrl
[MAC] Add missing icon support to NotebookBackend
convert ListBox.GridLines to bool
since ListBox has no columns and no vertical grid lines
[WPF] fix TextEntry PlaceholderText initialization
PlaceholderTextAdorner should be initialized after
the backend widget has bee fully loaded.
(fixes #329)
[MAC] add missing cursor position and selection support to TextEntryBackend
Merge branch 'extend-webview'
Merge branch 'add-notebook-features'
Merge branch 'add-list-gridlines'

Conflicts:
	Xwt/Xwt.Backends/IListBoxBackend.cs
Merge branch 'add-text-cursor-selection'
Merge branch 'fix-329'

Conflicts:
	TestApps/Samples/Samples/NotebookSample.cs