Additional client and server command line options

This adds a few options to the client and server binaries.

For clients, you can specify a --debug flag to instruct all servers to print information about this request. Useful for following the path of a single request.

Clients can specify --limit -- a maximum number of requests to execute. Useful when debugging, to just send a single request to the server.

This merge request also includes some pass-by-reference bugfixes in the server.