Use the copy composite operation when calling drawImage

This optimizes IMG_Load so that it just does a memcpy as opposed to try
to composite.  The resulting buffer will be the same, it just happens
that we don't need to do all of the work involved in compositing in the
first place.
Merge pull request #858 from ehsan/drawimage-memcpy

Use the copy composite operation when calling drawImage
remove unneeded sign correction from dlmalloc benchmark
fix test_debug
Added support for `glFrustumf`.
Added some symbol compatibility for OpenGL1.1.
Added implementations for
- eglTerminate
- eglDestroySurface
- eglDestroyContext
Stubbed out glTextEnvi
add mbishop
warn only once on glTexEnv*
hardcode arguments in benchmark js files, for easier debugging on them
handle malloc(0) and free(0) in corruption checker
simplify corruption canary
support realloc in corruption checker
allow changing frequency of corruption checks, and forcing a check irregardless of frequency
Provide error message on invalid command to emmake.

Previously, this would just throw an exception, now it provides
a reasonable error message.
Statically allocate the strtok state block so it doesn't trip up our leak detection.
Mix_Init
vertex array object support in gl emulation
glGetPointerv
TODO: multiple array buffers in vao (for each vertex attrib pointer separately)
add more glGetIntegerv constants