added dontRecomposite
SuspendEvents also suspends recompositing on CompositeDynamicObjectCollection
Issue: https://github.com/AnalyticalGraphicsInc/cesium/issues/1452
make `shouldRecomposite` 'private' as `_shouldRecomposite`
performance fixes
TimeIntervalCollection, DataSourceCollection, BillboardCollection, ImageryLayerCollection, LabelCollection, PolylineCollection, SensorVolumeCollection
Update CHANGES.md
Remove proxy from most default imagery providers.

ESRI and OpenStreetMap (OSM, Stamen, and MapQuest) all now support CORS headers directly.

Also remove `FeatureDetection.supportsCrossOriginImagery` and related checks which only applied to old WebKit versions (Safari before version 6).
Remove unused modules.
Merge pull request #1520 from AnalyticalGraphicsInc/removeProxyFromImagery

Remove proxy from most default imagery providers.
Merge pull request #1519 from AnalyticalGraphicsInc/getSetProperties

Replace get/set functions with properties: Collections
rename
Update CHANGES.md
Merge pull request #1523 from AnalyticalGraphicsInc/renameImageryCollection

centralBody.imageryLayerCollection -> centralBody.imageryLayers
Fix Primitive picking when appearance is closed and the geometry is on the surface.
Update CHANGES.md.
Fix CZML vertexPositions and directions processing

There were regressions in the load code as part of #1444.  Basically vertexPositions and directions can be arrays or objects, we were not handling the array case.
Move to b27.
Fix casing.
Iterate over _collections vs _collectionsCopy
Merge branch 'composite-performance-fix'