network: reimplment connection auto-connect strategy

This is a big change, all auto-connect strategy has
been rewrite, a new object named switchHandler was
created to dispatch such work. And there are also
many of other changes in following.

- connect computer suspend signal, just disable all
  notifications when is suspending or restoring, and
  reset device switches when restoring

- reset data when network-manager service restart

- ensure wired connection name consistent with
  current system language

- support autoconnect for vpn connections

- auto trun off vpn switch if there is no avtive
  vpn connection

- add autoconnect argument for NeedSecrets() and FeedSecret()

- destroy nmManager and nmSettings when stopping
  service to disconnect all signals on them

- remove dbus properties, WirelessEnabled, WiredEnabled
  and WwanEnabled

tower: https://tower.im/projects/15081ba156b14fa4bd6d9e82f91edff3/todos/1260cf94ace74669b2a35b887d518b26/
tower: https://tower.im/projects/8f19f0bf0e754f0b82ef2c24bc230973/todos/2b8a99e810dd442cb6206985384e0750/
tower: https://tower.im/projects/8f19f0bf0e754f0b82ef2c24bc230973/todos/38d3c99fb18440848fe754424c0dd4b9/
tower: https://tower.im/projects/8f19f0bf0e754f0b82ef2c24bc230973/todos/fc52725da95c42ca961bd45c79cec21a/
tower: https://tower.im/projects/8f19f0bf0e754f0b82ef2c24bc230973/todos/99c75b9736de4858b854e92aeba2c91e/
Change-Id: I60bcc03a5bc102ece14b979522e344f61738c9d2