make WCS comparison more permissive; WCS are most likely to be identical
if one has some info (e.g. equinox) and the other does not, so it is
better to warn than Raise for this case.
print->logging.debug and added a 32 vs 64 bit test
Merge pull request #96 from keflavich/wcs_permissive

Make WCS comparison more permissive