Merge changes I33ad04ee,I651d96a7,I0ef498ec,I88f4e539,I32c4e750, ...

* changes:
  Delete all EOTs in iptables commands and remove fixCommandString.
  Speed up FirewallController startup.
  Move NatController startup to iptables-restore.
  Further speed up creating child chains.
  Use iptables pipes when fetching tether counters.
  Use iptables pipes in BandwidthController startup.
  Improve IptablesRestoreController error logging.
  Support reading output from IptablesRestoreController.