Fix global color state tracking.

(Fixes #24. Thanks @seandepagnier)
implement scanlines for glDrawPixels
simplify glBitmap
add GL_UNSIGNED_SHORT_5_5_5_1 target pixel format
use hex for format debugging in pixel.c
use a power of two texture for bitmap operations
support multiple GLES library names
change cmake project name to glshim
add a PATH_MAX case for linux
remove texture bind abstraction in display lists
remove material abstraction
use PUSH_IF_COMPILING for enable/disable
standardize renderlist function naming
always update global color if not compiling
switch to calloc for renderlist init