Stop the connection heartbeat after the JS test has completed

- Leaving the heartbeat active caused an FFConnectFacts test to fail since
  verifyLastActive was unexpectedly getting invoked by the heartbeat
Update tests so they pass in TestSwarm

- Use relative paths to establish connections
- Don't assert the long polling transport is monitoring keep alives if
  XHRs have no onprogress event
Made the backoff time for Service Bus configurable

#2954
Adding support for WP81 and WPA81 targets.