Connection and disconnection: ModemManager Reference Manual

## Connection and disconnection

The process of requesting to connect or disconnect the modem is now split into two operations: creating a bearer with `CreateBearer()` in the `org.freedesktop.ModemManager1.Modem` interface and getting the bearer connected with `Connect()` in the `org.freedesktop.ModemManager1.Bearer` interface. These two steps are equivalent to the old ``Connect()`` method in the previous `org.freedesktop.ModemManager.Modem` interface.

The old ``Disconnect()`` method in the previous `org.freedesktop.ModemManager.Modem` interface is therefore also applied in a per-bearer basis through the new `Disconnect()` in the `org.freedesktop.ModemManager1.Bearer` interface.

This logic of splitting the connection logic allows ModemManager to create multiple bearers that may be connected to e.g. different access points (if the modem allows it).