Add ol.source.Vector#getFeaturesIterator function
Use goog.iter.some instead of ol.structs.RBush#forEachInExtent
Use goog.iter.filter instead of ol.structs.RBush#forEachInExtent
Reove ol.structs.RBush#forEach function
Use goog.iter.toArray instead of ol.structs.RBush#forEachInExtent
Use goog.iter.forEach instead of ol.structs.RBush#forEachInExtent