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
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
Add ol.geom.flat.linearRingsAreOriented
Add ol.geom.flat.linearRingssAreOriented
Don't automatically orient rings in ol.geom.Polygon
Add ol.geom.Polygon#getOrientedFlatCoordinates
Use oriented rings where needed
Don't automatically orient rings in ol.geom.MultiPolygon
Add ol.geom.MultiPolygon#getOrientedFlatCoordinates
Use oriented rings where needed
Add test for ol.geom.Polygon#getLinearRings
Create linear rings directly from flat coordinates
Create polygons directly from flat coordinates