openlayers/ol3 — pull request #2872 by fredj (2014-10-24 16:12:04+00:00)
Title: Remove the beforepropertychange event from ol.Object

See https://github.com/openlayers/ol3/pull/2865#issuecomment-60323004

propertychange events include the oldValue so remove the beforepropertychange
event type.