vcl: improve vcldemo & outdev test.

Change-Id: I1ebc3c3b3cffabc8ba446ecd45ac2d9b0d45aff1
vcl: Only load OpenGL shaders once for each context

Change-Id: Idbf9026c5e64ef41d4c913153dfddf36923ff7de
add some debug code that checks the returned pixel format

Change-Id: I44a1a8d97fecb7d371c4daa9888c56766087ec82
vcl: Fix a coordinate issue when getting a bitmap from a VirtualDevice

Change-Id: I06fef2765f2dc9d64a991385a984a4c75a1fd424
request a stencil on windows

Change-Id: Ib8f337d80c5576380344893c49c4fa0284f1dc4b
vcl: OpenGL texture creation debug.

Change-Id: I6a21c89329d9e9396ed16ce58b184339719adab7
vcl: use resetToReInitialize to avoid context problems on Windows.

It appears that we have to do this for VirtualDevices, where we have
freed / re-allocated the underlying resource, or we fail to switch the
current context, and render to the wrong place, before blatting a
blank texture over the top of it.

Change-Id: I0253f216ea7dc9786374dc83ca38f4f6295e3035