To get IE7 support, the OpenLayers.Format.JSON parser should be used. This leverages the native JSON.parse method where available. It does add extra weight to UTFGrid builds. However, as of this commit date, we lose large portions of US govt agencies when we exclude IE7.
I would think there would still be an error thrown here. Will put together a test to determine for sure, but I'd think that the default GeoJSON parser used by the protocol would choke on the UTFGrid json.
I think it should be the job of the layer to retrieve data for a given location (instead of the control). The first part of this change creates a `getData` method on the layer and updates the control to use this method.
The second part of this change removes the assumption that the data returned will be an simple object representing feature attributes. The UTFGrid specification doesn't say anything about the structure of property values in the optional data member. The examples given in the spec use string values. The default callback previously assumed that the data could be rendered in a two column table. I think it would make more sense not to make this assumption. With this change, the user must always provide a callback to do anything with returned data.
When the list of event types became unconstrained in 501b42228a, we lost the documentation for events that are triggered. This change adds the list of events triggered to the API docs for events properties.
In setMap, the layer gets the map's projection if it doesn't have its own. And since a layer can have a different SRS code than the map (but a compatible one, i.e. with OpenLayers.Projection.transforms[mapProj][layerProj] being OpenLayer.Projection.nullTransform), the axis order can be different.
This allows us to simplify the map and layer configuration, because now the projection also defines defaults for maxExtent, maxResolution and units.
This change also adds transforms for SRS aliases for EPSG:4326 and centralizes axis order information in OpenLayers.Projection.defaults.
