Corrected byteswap problem on error code decoding. Added a couple of new (EOS 20D) error codes, though we don't know their   meaning. We now treat a non-zero error code returned at offset 50 of the reply   packet as an error.
Corrected byteswap problem on error code decoding.
Added a couple of new (EOS 20D) error codes, though we don't know their
  meaning.
We now treat a non-zero error code returned at offset 50 of the reply
  packet as an error.


git-svn-id: 40dd595c6684d839db675001a64203a1457e7319@7916 67ed7778-7388-44ab-90cf-0a291f65f57c

msmeissn/libgphoto2,jbreeden/libgphoto2,gphoto/libgphoto2,gphoto/libgphoto2,msmeissn/libgphoto2,msmeissn/libgphoto2,jbreeden/libgphoto2,gphoto/libgphoto2,thusoy/libgphoto2,jbreeden/libgphoto2,jbreeden/libgphoto2,thusoy/libgphoto2,gphoto/libgphoto2,gphoto/libgphoto2,jbreeden/libgphoto2,thusoy/libgphoto2,gphoto/libgphoto2,thusoy/libgphoto2,msmeissn/libgphoto2,thusoy/libgphoto2,msmeissn/libgphoto2