Add ol.format.XSD.readBooleanString function
Add ol.format.XSD.readDecimalString function
Add ol.format.XSD.readNonNegativeIntegerString function
Merge pull request #1677 from fredj/xsd-from-string

Add ol.format.XSD.read*String functions
Add exports for ol.style.Circle
Add exports for ol.style.Icon
Add exports for ol.style.Text
Remove exports from ol.style.Image
Merge pull request #1678 from oterral/fix_exports

Add exports
Dispatch 'render' event in renderer.canvas.VectorLayer

The context property of the event only contains the vector rendering.
Add ol.layer.Heatmap class and example