Clip rendering to layer extent
Example demonstrating limited layer extent
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).
Making GetTileCoordFor methods public avaible

I am using tilegrid to request elevation data tiles side by side of a raster layer. It would be nice if these two method was public avaible such I could use the tilegrid to convert mouse coordinates to tile coordinates to request backend tiles. 

The elevation tiles are not shown as a layer directly but rather used to compute and show information in relationship to mouse curser or map view.

This would save me the time of adding another tilegrid implementation in my application specific context.
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.
Merge pull request #2978 from ahocevar/mapquest-zoom

Fix zoom levels for the MapQuest Street layer
Support OGC srs urns without an EPSG database version
Merge pull request #2979 from bartvde/proj-urns

Support OGC srs urns without an EPSG database version
Export ol.source.TileVector#getFeatures in built mode
Use lineDash in ol.style.Circle's and ol.style.RegularShape's stroke
Merge pull request #2980 from pgiraud/tilevector_getfeatures

Export ol.source.TileVector#getFeatures in built mode
Adding getFeaturesAtCoordinateAtResolution in ol.source.TileVector
For stars, use radius1 and radius2 in ol.style.RegularShape
Merge pull request #2982 from bartvde/radius1

Allow radius1 as an alias for radius in ol.style.RegularShape
Merge pull request #2981 from bartvde/circle-linedash

Use lineDash in ol.style.Circle's and ol.style.RegularShape's stroke (r=@fredj,@elemoine)
Correct olx.style.RegularShapeOptions definition
Merge pull request #2988 from bartvde/radius1-olx

Correct olx.style.RegularShapeOptions definition (r=@elemoine)
Merge pull request #2971 from elemoine/tilevector

Two ol.source.TileVector fixes
Merge pull request #2937 from tschaub/clipped

Clip layer rendering to limited extent.