DBus command to force Virtual Cable Unplug.

To workaround bugs in some client devices, provide a way
to force a Virtual Cable Unplug to be sent the next time
a device connects.

Provide an unplug-GFRM100 command which uses the new Unplug
DBus operation to send a Virtual Cable Unplug the next time
the remote control connects.

Change-Id: I96f60e4c8a1eb935760c5e78940072157aeb68a7
8 files changed