Improved glProgramUniform support

* OpenGL 4.1 style glProgramUniform functions are provided as mappings
  from an extension or emulation
* mapping functions now consider OpenGL ES and native support for iOS 5
* ShaderProgram uses glProgramUniform instead of the EXT version like
  in OpenGL 4.1
* Easy to query OpenGL version numbers in OpenGL::Tools added
* clean up in ACGL::init()
* namespaces in the extension file