Fix the bug with the disappeared pointer
more efficient huffman tree encoding, and fixed memory leak
fixes issue 32, could stop with error when using lossy_transparent with palette
rename makefile to Makefile
denser huffman tree encoding
Merge remote-tracking branch 'google-source/master'

Conflicts:
	src/zopflipng/zopflipng_lib.cc
Revert "GCD parallelization of filter selection"

This reverts commit 1eb3d0aefa00be257dd85e92e35735f1e0f1b3dd.