This is required for the substitution of different HTTP servers or the newer HttpServer.dll without having to commit to a particular implementation.
This is also required to write regression tests that involve the HTTP layer.
If you need to recompile, all you need to do is replace OSHttpRequest/OSHttpResponse references with IOSHttpRequest/IOSHttpResponse.
* Moved the SL asset type to content type conversion methods from ServerUtils to OpenSim.Framework.SLUtil
* Linked content type to asset type in AssetMetadata