Fix code consistency for signal strength in maemo6 telephony driver
Fix code consistency for signal strength in maemo6 telephony driver

This patch simplifies and makes maemo6 telephony driver code consistent
with libscnet API regarding SignalBarsChanged. RSSI percents and RSSI
dBs are not among the parameters when SignalBarsChanged emited.
Therefore, these parameters are removed. Names are changed to reflect
libscnet d-bus interface notations. Comments and debug information are
updated in places where units or operations are unclear.

ComputeCycles/bluez,pstglia/external-bluetooth-bluez,silent-snowman/bluez,pkarasev3/bluez,pstglia/external-bluetooth-bluez,ComputeCycles/bluez,ComputeCycles/bluez,silent-snowman/bluez,pkarasev3/bluez,mapfau/bluez,silent-snowman/bluez,pstglia/external-bluetooth-bluez,pstglia/external-bluetooth-bluez,mapfau/bluez,pkarasev3/bluez,pkarasev3/bluez,silent-snowman/bluez,mapfau/bluez,mapfau/bluez,ComputeCycles/bluez