…ine-rdp

* Fill gutters with color
* Detect RDP via DXGI flags
* Detect device changes via DXGI
* Properly treat selection and cursor changes as invalidations
* The D2D mode renderer used to redraw the entire viewport whenever
  the dirty rect is empty which happens when dragging a selection
* With the above fix in place we sometimes don't Present()
  so we now also need to sometimes not wait on the frame event
* Listen to const-buffer data being changed and redraw everything
* Stop setting the const-buffer on every frame

…ine-custom-shaders