WMSGetFeatureInfo control: add support for mutiple WMS services

[bartvde]

It would be nice if the OpenLayers.Control.WMSGetFeatureInfo control would support querying over layers from multiple WMS services.

I'll try and work out a patch for this.

[bartvde]

Tests pass in FF 3.5.5 and Safari 4.0.4.

Thanks for any review.

[bartvde]

patch includes tests

[ahocevar]

Bart, attachment:openlayers-2091.patch makes the following changes:

• Make it clear in the apidocs that with drillDown set to true, the text and request properties of the featureinfo event will only be from the last request issued
• Use an object instead of an array for the services in the request method. This saves us an extra loop.
• Renamed fixupStyleNames to getStyleNames and use it in a per-layer manner. Saves us some lines of code and makes it easier to read.
• The new getStyleNames method also made it possible to simplify signature of the buildWMSOptions method and move the layerNames and styleNames concatenation into that method. Saves us some code duplication.
• Changed the signature of the triggerFeatureInfo method so features comes last. Cosmetic change, seems more logical to me.
• Prepended features, requestCount and numRequest members with "_" and delet them after calling triggerGetFeatureInfo.

Tests still pass in FF3.5. Please commit if you agree with my modifications.

[bartvde]

(In [9874]) WMSGetFeatureInfo control: add support for mutiple WMS services, r=ahocevar (closes #2091)

[bartvde]

Thanks Andreas, I fully agree with your modifications and only corrected a typo in the comments.