BluetoothDiscoveryModel API fixes

- rename signal: newServiceDiscovered -> serviceDiscovered
- rename signal: newDeviceDiscovered -> deviceDisovered
- add parameter to deviceDiscovered signal
- improve documentation for above signals
- minor example fixes

Task-number: QTBUG-33678
Change-Id: I2f9223250ef844564c3e76a85adc25322867fd6e
Reviewed-by: Fabian Bumberger <fbumberger@rim.com>
Reviewed-by: Alex Blasche <alexander.blasche@digia.com>
Document the data roles offered by the BluetoothDiscoveryModel.

Change-Id: Ifba68d1980f6eedd030db38836be5a2d62a224b2
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>
Reviewed-by: Fabian Bumberger <fbumberger@rim.com>
Update QML type description for Bluetooth QML API due to API changes.

Change-Id: I30ae8567823e9d48a51654f18048bf66babc6e5a
Reviewed-by: Jerome Pasion <jerome.pasion@digia.com>
Reviewed-by: Fabian Bumberger <fbumberger@rim.com>