ee27bfa147
This refactors the RequestHandler code, to decouple RequestHandler behavior from the Server implementation. The goal is to make it easier to define additional Server implementations, in addition to just LibEventServer. This adds a RequestHandlerFactory function, rather than using a pure virtual method of the Server class. With the old model, you had to subclass each server implementation separately for each RequestHandler type you wanted to use, resulting in NxM classes if you have N server types and M request handler types. This also changes the behavior of the RequestHandler class somewhat: the code now only creates a single RequestHandler per thread, and uses that object for all request in that thread. Previously the LibEventServer code would attempt to create a new RequestHandler object for each request if supportReset() returned true. This was used by RPCRequestHandler. Now the RPCRequestHandler instead just resets itself automatically when necessary, without requiring external help from LibEventServer. contbuild test runs failed due to git server issues.