Adds support to encode and decode VP8. Note that a vp8 encoder and decoder need to be build into the jnffmpeg library in order for this to work, and prebuild binaries aren't ready yet.

Changes the default priority of Opus in the configuration, it's now on top. Removes the DVI4 codec formats, since they are not supported.

- Removes the DirectSound support from PortAudio in order to prevent issues with bad audio quality.
- Attempts to recognize USB PortAudio devices on Windows as such, ignores the virtual Microsoft Sound Mapper devices to avoid user confusion. Contributed by Vincent Lucas.

Adds FEC support for the SILK codec. Minor clean-ups in EncodingConfiguration and MediaConfigurationImpl.

Changes the EncodingConfiguration instance stored in MediaServiceImpl to one which contains global settings. Changes the names of some methods in EncodingConfiguration and MediaService to make their meaning more clear. Adds storeProperties() methods to EncodingConfiguration, makes EncodingsPanel use them.

Adds support for the IETF Opus codec (patch by Boris Grozev). Fixes a problem that prevented Jitsi from using formats that are disabled by default (pach by Boris Grozev)

Applies a patch from Boris Grozev that allows setting different codec configurations to different accounts. It is now possible to set entirely different codec preference for every account.