0.0.9: Fix minor FIN_WAIT2 resource leak

- Small patch to fix a minor FIN_WAIT2 resource leak, which can occur when clients disconnect from the
  jobson websocket API in a non-ideal way (that is, non-ideal with respect to the TCP spec)
- Added a default idle timeout of 10 minutes for all websocket connections (previously, it was 2^63)
- Changed the websocket implemented to report websocker errors in the DEBUG log rather than the ERROR log.
  This is because many websocket errors are connection errors, which occur even in nominal operation (e.g.
  clients with flakey connections)
- Websocket errors no longer result in the websocket session being manually terminated with no error code.
  Instead, the webserver (Jetty) handles the error code. This is so that timeout errors are correctly
  reported to clients with the correct timeout code (previously, it was reported as a "normal closure")