XML deserializer List<string>

[bluejack2000]

The same problem as described in issue 28 ( https://github.com/johnsheehan/RestSharp/issues/28 ) exists for XML deserializer too.

string has no parameterless constructor so it can't be instantiated.

My hotfix was to identify string types in CreateAndMap and return string without using Activator.

[ayoung]

If you can supply the fix in a pull request, I'll merge it in.

Added pull request #174