Avoid firing duplicate change events in ol.layer.Layer
No need for handleLayerChange in base layer
Avoid duplicate change event on visibility change
Remove unused handleLayerVisibleChange
Test change events on layer groups
Merge pull request #1349 from tschaub/fewer-change-events

Clean up layer change event handling.
Add missing "new"s in ol.structs.RBush
Merge pull request #1364 from twpayne/rbush-new-error

Add missing "new"s in ol.structs.RBush