libav: add PACKAGECONFIG for theora, libvorbis, speex and openssl

libav: add PACKAGECONFIG for theora, libvorbis, speex and openssl

Dropped libvorvis dependency because there is already a (better) builtin vorbis codec.
Don't confuse codec names: "vorbis" (builtin) and "libvorbis" (using external library).

Changes:
- add --enable-nonfree when faac or openssl are used
- add DESCRIPTION
- sort PACKAGECONFIG entries

Tested with libav-0.8.11 & libav-9.13.

Note: Be sure to have a recent version of bitbake (2014-06-11 or better) including this:
http://cgit.openembedded.org/bitbake/commit/?id=2e742c03e8dfdfa67899e7f5d579ed14bd87e139
It affects behavior of bb.utils.contains_any

(From OE-Core rev: 62eede9de6fa1c76fa97ca5c6ba2d31309759b10)

Signed-off-by: Matthieu Crapet <Matthieu.Crapet@ingenico.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>