pixdesc: add function to return pixel format with swapped endiannes
swscale: add support for endianness only conversion

Use bitfields in FormatEntry array to avoid wasting an int for each flag.
swscale: support endianness conversion for AV_PIX_FMT_XYZ12
Merge commit '74652af821d7e526a6541876a637fbf81261fa8e'

* commit '74652af821d7e526a6541876a637fbf81261fa8e':
  pixdesc: add function to return pixel format with swapped endiannes

Conflicts:
	libavutil/pixdesc.c
	libavutil/version.h

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit 'c1eb3e7fecdc270e03a700d61ef941600a6af491'

* commit 'c1eb3e7fecdc270e03a700d61ef941600a6af491':
  swscale: add support for endianness only conversion

Conflicts:
	libswscale/utils.c
	libswscale/version.h

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Merge commit '9cfa21c8c2b81146aab574f55c93f27e5c2d435c'

* commit '9cfa21c8c2b81146aab574f55c93f27e5c2d435c':
  swscale: support endianness conversion for AV_PIX_FMT_XYZ12

Conflicts:
	libswscale/swscale_unscaled.c
	libswscale/utils.c

Merged-by: Michael Niedermayer <michaelni@gmx.at>
Support decoding of Lagarith frame type FRAME_SOLID_COLOR.

Fixes bug 459.