added generate_audio script
ignore backup files
added generate_video script
Context.demux() accepts a single stream
Start making VideoFrame stand alone
Add PEP 3118 buffers
Start video generation example
Travis: fix requirements and pull assets
Skip memoryview test if memoryview doesn't exist
Pull SkipTest from nose
Merge branch 'testsrc' into develop
Merge branch 'develop' into frames
Can generate video from PIL

QuickTime thinks it is black.
Setup logging for all examples
Examples use mpeg4 so that QuickTime works
Tweaks errors and reprs
Merge branch 'video' into develop