[cairo] ARGB, BGRA, RGBA mess (was: Radial gradiant bug?)

[Chris]

OK, I've given up trying to hack libpixman and libcairo to use the byte
ordering that I need on all platforms.

It's pretty easy to change on a little endian machine because the alpha
byte is in the right spot, but on a big endian machine the alpha byte
position can not be easily moved around (I need it to be last not
first).  The alpha position is hard-coded and expected to be in a
certain location in both libpixman and libcairo.  From what I can tell
anyway.

If anyone comes up with a clean solution please let me know because I
would like the performance of not having to twiddle these bytes around.
Right now I have to render to a buffer then scrub all the pixels to the
byte ordering that I need.

Normally I wouldn't mind making the needed changes to these libraries
but all those macros are really infuriating.

-- 
// Chris