add error handling:
* deprivilege the qubes rpc service completely
  * find out as what user it runs, we don't want it to run in the same
    security context as the user of the console
  * it looks like it runs as "user", this may require some sudoing
    into an unprivileged user
* write tests for all those handled error cases, to ensure the code is
  completely covered by the tests
* cancel if read from qrexec pipe takes too long, or if write takes too long
* cancel connection with the browser if reado/write to client takes too long
* rate limiting for clients
* SSL
* authentication
* documentation on how to scrape with this thing
