Build giflib 4.2.1 instead of 5.0.4, matching gif_lib.bi
Internal: remove CHAR_CARET constant.
CHAR_CARET and CHAR_TIMES/CHAR_STAR are all set to 42 ('*'), while you would expect CHAR_CARET to be '^' (94, which has been called CHAR_CART).
Remedy this confusion by removing CHAR_CARET and changing three refrences into CHAR_STAR or CHAR_TIMES, whichever is more appropriate.
Update jpeglib headers and fix the example

The new jpeglib.bi header supports jpeglib 6.2, 7.0, 8.4 and 9.0.
The version can be selected through the __JPEGLIB_VER__ #define,
and it defaults to 9.0 (the version that will be included with
FB release packages).

Supporting multiple versions is necessary because they are ABI
incompatible and e.g. Ubuntu 13.04 apparently has versions 6 and 8,
but not the latest version 9. But it will be different for other
distros, not to mention DOS/Win32...
Update IL header #inclibs/externs for the libs built with MinGW/MSYS
headers: Merge gif_lib5.bi into gif_lib.bi, similar to jpeglib.bi
Go back to building giflib 5.0.4

since that is the latest version and FB's gif_lib.bi now defaults to
it and optionally allows switching to gif_lib version 4 for anyone
with other binaries.
Merge remote-tracking branch 'origin/master'