Adding support for running tests on Android using the emulator.
Support grabbing screenshots for Android via adb.
Start a xvfb if a display doesn't exist.
Force xvfb to 24bit color.

xvfb must use 24bits otherwise you get a "failed to create drawable" error from
the emulator. See the following bug for more information
https://bugs.freedesktop.org/show_bug.cgi?id=62742
Updating Android Developer toolkit and Chrome Driver.
Adding intent to call inside apk file.
Find out if the intent started.
Bail if Android devices are detected.
Better detection of emulator crashing.
Split the test run into two parts so it completes.
Fallback to Date.now() if window.performance.now() fails.
Change the timeout to 5 minutes as tests are very slow on Android.
Temp commit, don't push upstream.

Conflicts:
	.travis.yml