First working test of stdin of webworker

[PaulKinlan]

[DON'T MERGE] I had to disable closure compiler.
[DON'T MERGE] I mistakenly pretty printed the tests.

Creates a RingBuffer so that we can continuously pipe data to ffmpeg in a webwork.

• Client creates a ring buffer to pipe the data to.
• Client posts the shared array buffer to the worker before the first run,
• FFmpeg needs to init the stdin for some reason.
• When ffmpeg needs data from the buffer it reads 1 char from stdin.

[tpetry]

Why is only one byte read each time from the buffer? This sounds awfully slow for large files, a 20MB video would be 20 million calls to the ring buffer.