Added Structual SIMilarity calculation in a JS file. Used for checking
SSIM between contiguous frames in a near-frozen frames subtest of
camtest.js.
Changed statement on where SSIM comes from and what we use from its Matlab code.
Merge pull request #154 from GoogleChrome/cameratest_detect_frozen_frames

Added frozen frames detection in test-rtc based on Structual SIMilarity calculation.
fixed according to comments
Set Opus as Preferred codec on apprtc for Chrome on Android
Add ability to download a random file with a given size from any domain.
Merge pull request #176 from GoogleChrome/add-download-file-from-any-domain

TestRTC: Now generates random data with no cross domain limitation from: /test-download-file/\d?\d00KB.data
Removing preferred send codec setting for chrome android.
Merge pull request #173 from GoogleChrome/apprtc-opus-mobile

Set Opus as Preferred codec on apprtc for Chrome on Android
Merge pull request #158 from GoogleChrome/fixjshint

Peer2Peer - Fixed all JSHint errors which wont affect (mostly) the planned refactor to classes + some tidying
New peer2peer UI
added logic for resolution selection buttons
fixed conflicts