Add ol.structs.IntegerSet
Refactor ol.structs.IntegerSet to use a packed array
Add initial ol.structs.Buffer
Add ol.structs.IntegerSet.toString
Extent equalArray to consider NaNs to be equal
Replace unused entries with NaNs
Reverse order of arguments to set and s/index/offset/
Allow rectangles to be empty
Add ol.Rectangle.isEmpty
Add ol.Extent.createEmptyExtent
Add ol.Rectangle.extendXY
Add missing variable declaration
Add initial ol.geom2.PointCollection