Bug 930242 - Consolidate ogg moz.build files. r=ted

Replace recursive build files with a single pair in the top
level source for better readability and parse time.
Bug 930228 - Consolidate vorbis build files. r=ted

Replace recursive build files with a single pair in the top
level source for better readability and parse time.
Bug 930228 - Move vorbis define to moz.build. r=ted.
Bug 930718 - Move vorbis Solaris patch to moz.build. r=ted

We've been carrying at patch against vorbis to define HAVE_ALLOCA_H on
Solaris from bug 469639. Upstream doesn't want to take it since their
build system already handles this case. It's therefore cleaner if we
handle it in our build scripts as well.