* Fix sizing on the desktop

* Try overriding QPaintDevice to obtain the background pixmap
  - Will get rid of the double painting
  - Will possibly allow calling XSetBackgroundPixmap without having to call XClearWindow()
  - Might allow paints that result in an identical background pixmap to be discarded

* Remove X11EmbedContainer's dependency on SelectionManager
  - X11EmbedContainer needs to be a self-contained QX11EmbedContainer implementation

* Add checks for XRender presence and fail nicely if necessary
* Don't do all the extra QX11EmbedContainer hacks if the client window is of the same depth
* Handle taskId clashes better

* Misbehavior of certain applets within the plasmoid protocol or vice-versa. (Still needs investigating)
