Create convenience Layer for SOS

[bartvde]

Create Layer.SOS so that it is easier for people to use the SOS support

[bartvde]

One thing to note about this patch is that in order to get the load events right, I had to add a property to the Fixed strategy so that it optionally does not trigger the loadstart event. This is because the SOS layer will first do a GetCapabilities request before it can activate the strategy, so the loadstart event is triggered by the layer instead before retrieving the GetCapabilities.

Tests pass in FF 3.6, IE8 and Safari 4, please review.

[erilem]

Bart, is the change to the Fixed strategy required? Is it really an issue that loadstart occurs after the reception of the capabilities? /me not a big fan of adding such "random" option. The rest looks fine to me.

[bartvde]

Hi Eric, IIRC it was necessary to get the layer to play nicely with the LoadingPanel addin. Do you have any other suggestion on how to accomplish that?

[erilem]

Replying to bartvde:

Hi Eric, IIRC it was necessary to get the layer to play nicely with the LoadingPanel addin. Do you have any other suggestion on how to accomplish that?

Personally I would have kept the capabilities related stuff outside the layer.

[bartvde]

Agreed, so I am changing the state to Needs More Work, since I don't have the time before the 2.11 release.

[erilem]

Replying to bartvde:

Agreed, so I am changing the state to Needs More Work, since I don't have the time before the 2.11 release.

So I'm also setting Milestone to Future.