Set the loop type to setTimeout

- The polymer elements lead chrome to believe they are running in the
  page appropriately. AwesomeWebSocket detects it is NOT running as a
  chrome extension (AwesomeWebSocket uses "chrome.extension" to test).
  Added ability for caller in AwesomeWebSocket to set the loop type.

  Pull request here:

  https://github.com/glg/awesome-websocket/pull/7

- This change sets the loop type to "setTimeout"