Allow application developers to modify cursors

With this change, cursors can be set on the map target again.
Turn off rotation because Google does not support it
Merge pull request #1685 from ahocevar/google-no-rotation

Turn off rotation because Google does not support it
Show how to use ol.Feature#setStyleFunction in the icon example
Merge pull request #1686 from elemoine/icon-example

Show how to use ol.Feature#setStyleFunction in the icon example
Add MultiPoint to modify example
Check geometry type instead of `instanceof`
Fix MultiPoint modify
Merge pull request #1689 from tonio/fix_modify

Check for geometries type instead of `instanceof`
Add detection of canvas line dash support
Use ol.BrowserFeature.HAS_CANVAS_LINE_DASH in ol.render.canvas.Replay
Fix handling of line dash state in ol.render.canvas.Replay
Merge pull request #1684 from ahocevar/ie-cursor

Changing pointer cursor in examples is broken
Use protocol relative URL for OSM tiles
Merge pull request #1692 from fredj/osm-tiles

Use protocol relative URL for OSM tiles
Use protocol relative URL in ol.source.MapQuest
Use protocol relative URL in ol.source.Stamen
Save replay group, even if it is empty
Only replay replay group if it is not empty
Merge pull request #1695 from twpayne/fix-render-node-leak

Save replay group, even if empty