[opus] bug reports and missing license headers

[Ralph Giles]

Sergey,

I've pushed a version of your OPUS_EXPORT fix to the opus repo. Can you
please test your build against git://git.xiph.org/opus.git@1.0.x and
verify your issues have been resolved? I'd like to release what we have
there as 1.0.2 in a few days.

BTW, the WORDS_BIGENDIAN define in chromium's opus.gyp is wrong. This
has no effect because the opus code doesn't use the symbol, but since
x86 and arm-android are little endian, it definitely shouldn't
unconditional. I suggest removing it.

Also, the opus.h wrapper in
http://src.chromium.org/svn/trunk/third_party/opus/opus.h seems to be
redundant. If USE_SYSTEM_OPUS isn't defined, opus.gyp only exports
-Isrc/include to dependencies, and if it _is_ defined, it exports
whatever pkg-config returns for the system include path. In neither case
will this header be picked up; I suggest just removing the file.

 -r