* added get_bound_framebuffer function to pipeline to get the currently active/bound framebuffer
 * added invalidation functionality to image (images are automatically invalidated on nonrecoverable errors -> images are only valid if they have a valid/usable opencl buffer)
 * extended framebuffer destroy_images to completely clear the framebuffer (empty images container, reset depth and stencil buffer to nullptr)
 * fixed operator& for EVENT_TYPE
 * fixed texel_mix in oclr_image.h (uses custom linear_blend now instead of OpenCL built-in mix function due to implementation issues)
 * version bump to 0.0.3 (due to forthcoming commit)
 * added oclraster support library:
   * this is mostly a port of the a2elight gfx2d rendering code and gui system to completely use oclraster's rendering code (there is no OpenGL code in here!)
   * purpose of this project is to test oclraster with more advanced rendering code while also adding more "sample code" on how oclraster can be used (+also providing a nice ui for samples)
   * added gfx2d support kernels
   * added DejaVu fonts (see LICENSE in data/fonts/)
   * added a2elight gui theme files
   * note that this library is still very much wip (gfx2d should be fully functional, gui is completely defunct right now)
   * also note that this is a completely separate library to oclraster and is not required to use oclraster!
 * fixed file permissions