Add ol.Observable#getRevision
Add ol.Observable#dispatchChangeEvent
Use inherited dispatchChangeEvent and getRevision in ol.source.Source
Use inherited dispatchChangeEvent and getRevision in ol.Feature
Use inherited dispatchChangeEvent and getRevision in ol.geom.Geometry
Use inherited dispatchChangeEvent in ol.layer.Base
Fix drawinteraction example
Parse out-of-spec CRSs generated by GeoServer
Merge pull request #1565 from elemoine/draw

Fix draw interaction example
Merge pull request #1563 from twpayne/revision-in-observable

Move dispatchChangeEvent and getRevision into ol.Observable
Merge pull request #1566 from twpayne/geoserver-geojson-crs

Parse out-of-spec CRSs generated by GeoServer
Add ol.format.OSMXML and ol.source.OSMXML