fix minor typo in comment
add new regression tests that emit c4 codes in addition to generic codes, two new c4 code printing functions and some fixme notes also added
fix 16 and 32 bpp c4 code issue that could happen if a very large DUP code was 1 pixel over the max c4 size, add test cases and extra checks
fixup nasty encoding issue with a DUP code followed by a SKIP code, the skip num can only be folded into the last DUP code in a set of split codes, add test case
move segment pixel count for 32bpp COPY op outside of the emit code loop to avoid crash in testEncodeHugeCopyThenSkipAt32BPP, test case does not pass yet
apply skip after fix to 32 bit COPY c4 code, test case now passes