Add missing 'undefined' in type cast
Set default 'tracking' property to false
Merge pull request #805 from fredj/cleanup

ol.Geolocation and ol.DeviceOrientation cleanup
Only render and cache tiles that have features
Merge pull request #808 from ahocevar/no-empty-tiles

Don't render/cache tiles with no features. r=@tschaub
Do not use a fixed tile grid for vector rendering

Instead, we create a new tile grid whenever renderFrame is
called, no animation is active, and the resolution is not in the
tile grid already. This gives better rendering results because
we get vector tiles at native resolutions.
Separate method for updating the tile cache
Do not add resolutions while interacting
Use binaryInsert instead of sort
Tile grid and cache for one resolution only
Do not render tiles during animation and interaction
Adding comment about MIN_RESOLUTION
Fixing requires
Simpler tile coord access now that we only have one resolution
Need to take units into account
Calling callback in kml tests

Also reordering things so we have `expect(got).to.xmleql(expected)`.
Calling callback in GML v2 tests
Calling callback in GML v3 tests
Calling callback in WMS capabilities tests
Get rid of unnecessary `waitsFor` function

This was a relic from the Jasmine tests.  Mocha tests have a built-in timeout.  Async tests are registered with a function that takes a callback.