* Teach src/http.c to recognise new HTTP headers
      X-Until-Event: QueueStatusComplete
      X-Maxtime: 1000
    * Teach src/http.c to operate a timeout a bit differently.
    * Teach src/astmanproxy.c to mark completion only if requested header seen.
* Update HTTP documentation to mention new feature
* HTTP method now waits for end of Headers/POST-data before executing request.
* Also fix HTTP POST input method to understand new buffering better (still not perfect!)
Update to version 1.28.1