Rewrite the audio/video encoding components for BigBlueButton.

I've been working on this for a while, and it's adapted from code that
has been fairly well-tested on a wide variety of recordings. I've found
it to do a more accurate job of combining multiple webcam files, and it
should be more accurate in the audio as well.

Another key feature is that it does fewer re-encoding steps during video
processing, which should both speed it up and hopefully improve quality.
The settings on the VP8 encoder have been tuned somewhat as well.
Add a video quality bump when deskshare videos are present.
Add missing license header to edl.rb
Reset the offset to 0; the new scripts seem to have better sync?
Bump the max difference for audio stretch up to 5%
Update the ffmpeg version check in bbb-conf
Change the background color of the video area to white to match

The new scripts render the videos over white, so you get occasional
black bits sneaking in without this.
Merge branch 'master' into language-button-usability
Merge pull request #243 from kepstin/recording-rewrite

Recording rewrite
Add a big fat warning about the implications of leaving demos installed.
Merge pull request #244 from kepstin/bbb-demos-warning

Add a big fat warning about the implications of leaving demos installed.
Merge pull request #241 from mconf/language-button-usability

Fixed the style of the language selector
Change the GetRecording for demo 10
Merge branch 'master' of https://github.com/bigbluebutton/bigbluebutton
Merge pull request #245 from jent46/master

fix issue in the demo10_helper.
Logout URL was never called when API signOut call fail.
update locales
Merge branch 'master' of https://github.com/bigbluebutton/bigbluebutton
Merge pull request #247 from jent46/master

Update locales
delete transifex dir in locales