Rename layerFilter option to layers and accept array
Rename ol.source.BingMapsOptions style property to imagerySet

To match the Bing Maps terminology
Merge pull request #1273 from tschaub/select-layers

Rename layerFilter option to layers and accept array for select interaction.
Determine the callback count while iterating through all layers

Previously, if a layer didn't have a `getFeature*ForPixel` type method, the loop count would be decremented.  This means that all layers would not be considered.  Instead, the callback count should be incremented before requests are made and decremented in the callback.
Merge pull request #1274 from tschaub/callback-count

Issue calls to get feature/info for all layers.
Getter and setter support for bindTo
Add tests for ol.Object#bindTo getters and setters
Remove 'valueAsNumber' property from ol.dom.Input

Use bindTo.transform functions instead
Notify target object after transform functions change
Merge pull request #1275 from fredj/bing_style_param

Rename ol.source.BingMapsOptions style property to imagerySet
Merge pull request #1198 from fredj/bindTo_transform

ol.Object#bindTo: getter and setter
Move apidoc CSS style out of layout.css
Minor apidoc updates