Implement #268 on branch 2.x
Don't use ffprobe json output to support older ffmpeg versions
Update static ffmpeg URL for tests
Implement set methods for binary paths, closes #279
Cleanup path setting API and docs
Add .native() method, closes #247
Add multiple output test
Make test suite pass jshint
Remove withStrictExperimental() and make it automatic
Use local ffserver for RTSP/HTTP input tests
Use strict experimental with -acodec vorbis
Use vorbis codec in multiple output test
Add availableEncoders and check for experimental codecs before running
Update travis initialization

- Install ffmpeg package from apt-get (to get ffserver)
- Use static ffmpeg build from ffmpeg.gusari.org
Wait for ffserver to be ready before running tests