Fdo Provider Capabilities xml fix

[jng]

The fix to #1050 has revealed that Maestro has been working with incorrect provider capabilities xml for quite some time. As a result, features which rely on this xml output, such as the Expression Editor may not function properly against > 2.1 servers in its current form.

However, changing the deserialization logic to match the output from > 2.1 servers will simultaneously break <= 2.1 servers (as they are still outputting the incorrect xml)

The solution as suggested by Tom Fukushima, is to transform the xml into its pre-2.2 form before deserialization only if we're connecting to a <= 2.1 server.