depends: add mess of depends
depends: set default android configure options
depends: set some sane defaults for arm+linux
depends: clean up the built-in mess and test properly instead
depends: ffmpeg needs our ldflags
depends: point ffmpeg to the correct yasm

This should be fixed so that we check for a build-side yasm instead of
just assuming it's there.
depends: don't link libcdio unless optical is enabled
depends: remove android hack for python now that correct libdeps are defined
depends: add liblog check, it may not be included by the toolchain
depends: revert droid changes in CStdString

This way it builds fine with crystax and vanilla ndk.
depends: fix broken pyo sources in darwin
depends: fix android packaging
depends: fix android path after depends move
depends: fix osx project
depends: fix ios project
depends: mark our wrapped functions as used

otherwise they get stripped when enabling dead code stripping
depends: mark our wrapped implementations as visible

otherwise they get stripped when setting default visibility to hidden