Add USE_CORE_CONTEXT option to CMakeLists.txt, defaulting to false.
Update most of the hardcoded_shaders to #version 330.
Update two more hardcoded_shaders to #version 330.
Remove the linker flags lines that were killing debug info in VS2010.
Use a static array to sub in for the core-not-permitted glPush/PopAttrib.
Remove two glLineWidth calls.