This resolves the problem where eyes and hair would turn white on standalone configurations
When a client receives body part information, for some insane reason or other it always ends up uploading this back to the server and then immediately re-requesting it.
This should have been okay since we stored that asset in cache. However, the standalone asset service connector was not checking this cache properly, so every time the client made the request for the asset it has just loaded it would get a big fat null back in the face, causing it to make clothes and hair white.
This bug did not affect grids since they use a different service connector.
* OnQueueEmpty is still called async, but will not be called for a given category if the previous callback for that category is still running. This is the most balanced behavior I could find, and seems to work well
* Added support for the old [ClientStack.LindenUDP] settings (including setting the receive buffer size) and added the new token bucket and global throttle settings
* Added the AssetLoaderEnabled config variable to optionally disable loading assets from XML every startup. This gives a dramatic improvement in startup times for those who don't need the functionality every startup
