Attributes and uniforms

• Matrix overloads for setUniformValue() with 2x2 and 3x3 GLfloat arrays. [Done: 5cff63b2]
• Generic setAttributeArray() that can set the type to GL_FLOAT, GL_UNSIGNED_BYTE, etc. [Done: 5cff63b2]
• Setting matrices on attributes; e.g. GLfloat m[4][4]; setAttributeValue(attr, m); [Not needed: setAttributeValue() has an override that can already do this].
• Setting attributes to vertex buffer offsets. [Done: 5cff63b2]
• Enumerate list of attributes and uniforms.

Shader compilation

• hasShaderCompiler() to query the GL_SHADER_COMPILER option to glGet().
• Binary shader/program API's (see also QTBUG-7490).

Cross-program scenarios

• Attribute enablement state tracking to avoid unnecessary enable/disable calls.
• Attribute setting that is disconnected from a specific program.