Make loadFeaturesFromUrl accept an error callback
Make createTileCoordTransform return identity func

This makes ol.tilegrid.TileGrid#createTileCoordTransform return the identity function. This makes it possible to use ol.source.TileVector with an ol.tilegrid.TileGrid (as opposed to an ol.tilegrid.XYZ).
Add WMS GetFeatureInfo reader format
Add tests suite for GetFeatureInfo format
Make GetFeatureInfo format pass ol2 test suite
Change format name to WMSGetFeatureInfo
Renaming & better typing
Export readFeatures method
Restore proj4 state after tests
Fix zoom levels for the MapQuest Street layer

A typo in 65b8e0f91576e521606d906ecdfa9dffd2159dcb introduced this bug.
Before that, 18 zoom levels were used. Now we're using 19, which appears
to be available with full world coverage.
Support OGC srs urns without an EPSG database version
Export ol.source.TileVector#getFeatures in built mode
Adding getFeaturesAtCoordinateAtResolution for ol.source.TileVector