* added (wip) gl_cmp sample, which will allow for direct opengl/oclraster comparison (still need to fix some camera issues)
 * added (wip) fxaa implementation (currently this is kind of working, but still disabled by default)
 * added image_write support for native and buffer-based images (identical to the opencl write_image* functions)
 * fixed AMD platform issues (AMD only allows a max alignment value of 128, even though 4096 is required -> set image_header alignment to 128, but still use 4096 internally; this is luckily not much of an issue, as only the first few bytes are used)
 * increased binning stage queue buffer size to 128 MB (from 64 MB)
 * use max possible batch count in the rasterization program (as this is fully working for a while now)
 * fixed/improved framebuffer writes in the rasterization program (moved to an outer loop, as writing in the inner loop is not necessary)
 * updated + cleaned up simple sample (+moved shader programs into one file)
 * updated for latest SDL2 changes (touch/finger event changes)
 * lowered opengl requirement to 2.0 on os x (other platforms will use the drivers default version)
 * fixed core::wrap (should check for < 0, not <= 0)
 * added core::set_random_seed for the random generator in the core class
 * removed stereo flag from the config file, as it serves no purpose
 * some cleanup
 * version bump to 0.0.3-d3