TestRTC: Tests belong to a suite now.

This is pre-refactoring for the collapsible ui to allow the user to explore the errors.
Add mock setTestProgress and other cleanups.
Fixed JShint errors and switched to unused:vars.

Switch was due to when implementing interfaces one often does not
used certain values on purpose. Vars mode still checks for unused
variables and functions but it will ignore unused parameters.
Leave jshint unused as true. It actually only complains on the last parameters.
Merge pull request #188 from GoogleChrome/testrtc-clean

TestRTC: adding concepts of test suite and test progress.