Merge pull request #96 from hwhw/ffi-framebuffer-native

FFI interface for Linux framebuffer (eink-oriented for now)
Merge pull request #97 from hwhw/ffi-framebuffer-native

fixes for 16bpp framebuffers (Kobo)
fix default full refresh
since full refreshtype is 1 now, after removing the ‘NOT’ operation
in the old einkfb.c#L101
Merge pull request #98 from chrox/master

fix default full refresh
fix a miscalculation for physical rect coordinates
further addition to rotated rect calculation: adapted width/height
rotation correction for Kobo framebuffers