Add BluetoothInterface class to Solid's NetworkManager backend

Review Request #101172 - Created April 22, 2011 and submitted

Lamarque Souza
203584, 209624, 261191
This patch is the first step to implement tethering in Plasma NM. 

Tethering is term used to describe the use of a bluetooth device as the mean to access the Internet. There are two types of Bluetooth networks in tethering: DUN (Dial up Network) and PAN (Personnal Area Network). Both are very similar from Plasma NM point of view. In DUN you can use the bluetooth device (usually a cell phone) as a dial up modem (/dev/rfcomm0).

The patch slightly changes GsmNetworkInterface class to let BluetoothInterface inherit from it.
Tested against KDE SC 4.6.2, works with Gsm phones. Support to Cdma phones still missing.
Lamarque Souza
Lamarque Souza
Review request changed