GLEW 1.5.6 adds support for OpenGL 4.1, fixes bugs
* New features:
o Support for OpenGL 4.1 * New extensions:
o GL_ARB_ES2_compatibility
o GL_ARB_cl_event
o GL_ARB_debug_output
o GL_ARB_get_program_binary
o GL_ARB_robustness
o GL_ARB_separate_shader_objects
o GL_ARB_shader_precision
o GL_ARB_shader_stencil_export
o GL_ARB_vertex_attrib_64bit
o GL_ARB_viewport_array
o GLX_ARB_create_context_robustness
o GLX_EXT_create_context_es2_profile
o WGL_ARB_create_context_robustness
o WGL_EXT_create_context_es2_profile
