Improvements to wifi related functions in acts and sl4a.

Handle wifi connected intent in sl4a better:
  Framework sends two identitcal events every time wifi is connected.
  Handle this so sl4a client only gets one event.
Add WifiNetworkDisconnected event in sl4a.
Fix an uncaught exception issue in HttpFacade.
Add set system time function to sl4a.
Sort pop_events results in event_dispatcher.
Add two error handlings in flashutil.

Change-Id: Ib0e354b8587eddbd75eaf7ddc34eeb09effb45a2
3 files changed