add test make target
compare color value in blitbufer tests
add half done ffi pic module
fix fail on init of tesseract
Merge pull request #91 from houqp/houqp-master

half done ffi pic module
Merge pull request #92 from chrox/master

fix fail on init of tesseract
use more precise RGB to gray conversion

we use this:
gray8 = rshift(4897*red + 9617*green + 1868*blue, 14)
Merge pull request #93 from hwhw/blitbuffer-conversion

use more precise RGB to gray conversion
add back missed sample jpg file for unit test
fix: convert emulator dimension from string to number

* also add comment in blitbuffer module
Merge pull request #94 from houqp/houqp-master

convert emulator dimension from string to number
add FFI linux framebuffer interface
Merge remote-tracking branch 'upstream/master' into ffi-framebuffer-native
remove RGB16

we won't likely use it, it is full of bitops, thus pretty slow
fix accidentally deleted types
one type deleted that really is gone now
bugfix for value setting
factor out POSIX API
blitbuffer with much more optimized blitting

this introduces the ability to implement n:m bpp optimized blitting.
This allows for a major speedup. Comes with implementation especially
for from/to 4bpp blitbuffer blitting.
use blitbuffer API for conversion

now that blitbuffer API for A8 format exists, we can use the output
of mupdf directly.