Add support for rendering images into a native surface object
Add some Menu docs
Add support for multi-size icons

And added support for that in the GTK backend.
[GTK] Properly scale stock icons
[GTK] Added support for creating an image from a stockId
Add Width and Height properties to Image
[GTK] Fix stock icon rendering issues
[Xwt] Correctly handle a returned value of DBNull.Value

If we get this value we should treat it as null and return the
defaultValue.

Prevents a typecastexception when trying to cast DBNull.Value to
'T'.
[WPF] Fix infinite loop in clipboard class
[WPF] Add scrollbar and slider backends
[WPF] Widget placement fixes
[WPF] Track api changes
Merge remote-tracking branch 'upstream/master'