Removed complete bchannel handling from chan_lcr

The remote application interface does not allow any bchannel to be
exported or imported. Audio traffic via socket interface is used instead.

The joinremote instance became obsolete and is removed.

The remote action (routing) became obsolete, use interface.conf instead.

The handling of loopback device became obsolete and was removed

The chan_lcr does not rely on mISDN anymore, that means:
- can be used with GSM and without mISDN at all.
- chan_lcr can be used as internal extension of LCR (e.g. SIP phone)
  (chan_lcr can be handled as any other interface)
- no loopback device to be used anymore.