TRAC #11410

Add Program::getSamplerType() and internal machinery to track the reported sampler uniforms.
Make State::samplerTexture into a 2D array with a dimension for sampler type.
Context::applyTextures queries the sampler type and asks for the right texture.

Author:    Andrew Lewycky
Signed-off-by: Shannon Woods
Signed-off-by: Daniel Koch

git-svn-id: https://angleproject.googlecode.com/svn/trunk@25 736b8ea6-26fd-11df-bfd4-992fa37f6226