Shader moved to 1.10 subdirectory and a new version for 1.40 added.
At the same time call to glPolygonMode removed as it caused errors with
core context (and seems to not be needed).
REVIEW: 110572
CoverSwitch uses new concept of combining a custom fragment shader with the
built-in generic vertex shader. This shader is used to render the reflection
plane on top of the reflected windows.
The fragment shader uses two uniform colors for front and back and interpolates
between them based on the texcoords (which are not used for texture lookup).
The reflection plane vertices could be buffered.