Ports of hso/icera/mbm dialing logic to GTask

[Aleksander Morgado]

Hey,

These patches implement the dialing logic in the HSO, Icera and MBM plugins based on GTask. These plugins have a very similar bearer dialing logic, so ported all of them together in the same series.

  [PATCH 1/5] hso: port dial_3gpp() to GTask
  [PATCH 2/5] hso: use a 60s timeout to wait for connection unsolicited...
  [PATCH 3/5] hso: make report_connection_status() a separate logical...
  [PATCH 4/5] icera: port dial_3gpp() to GTask
  [PATCH 5/5] mbm: port dial_3gpp() and disconnect_3gpp() to GTask