This removes the WorkerThread class and many of the complications around it.
Instead of having a generic worker, there is now the `QueueRunnerService` which takes on all the resposibilities for handling queued tasks.
This is one step towards removing `FIXMEGlobal`
Re-implemented everything using ASP.NET.
Changed some requests to use JSON instead of FORM data.
Some work towards deleting the FIXMEGlobal instance.
Auth is missing, XSRF does not work correctly.