Added notes to documentation and adjusted OpenGL example as a workaround for the side effects of making static functions that require a context work. If the user wants to make use of both sfml-graphics and OpenGL, they should make sure sf::Texture::getMaximumSize() and/or sf::Shader::isAvailable() are called at least once before setting their final context active as those functions will cause a context switch the first time they are called.
Replaced GLEW with loader generated by glLoadGen, restructured GLExtensions.hpp for easier extension bookkeeping, make use of GLEXT definitions in Shader.cpp and Texture.cpp as well, replaced GL_MAX_TEXTURE_COORDS with GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS, implemented flags for requesting a debug or core/compatibility profile context, added warnings to all context creation implementations to warn the user of an incompatible mismatch between the context they requested and the context that was created, changed the default context version from 2.0 to 2.1.
Implemented methods to retrieve the OpenGL handles from sf::Texture and sf::Shader.