Add GDI+ fallback for ICC profile extraction

Also, fix some sundry ICC profile bugs, including a rather serious
Windows color engine bug where DIBs must be incorrectly marked as RGB
order (instead of BGR order) for color transforms to produce the correct
results!

The GDI+ fallback is surprisingly simple, and was primarily added so I
could have a second point of testing on problematic images.  While the
cause later proved unrelated to FreeImage or GDI+ (it actually has to do
with CMYK-format images), I am quite happy to have a GDI+ fallback in
this case.