fixed stereo input
Added progress bar with 1 second timeout to ensure buffer has time to fill up
fixed according to comments
renamed this.inputBuffer to this.lastInputBuffer
shortened variable names and remove temp assignment of this.lastInputbuffer
moved testfinished to stopCollectingAudio() and added back stereo mic message
Renamed back to lastInputBuffer.

More descriptive of what the variable holds.
Merge pull request #195 from GoogleChrome/enableStereo

TestRTC: Mic test now has expectations that can fail (fixes issue 197) and stereo is properly tested.