Changed Not Detectable to Not Found
Fixed bug not returning correct value in getRange

When [device getRange:YES] was called and either no device was set or
it was not able to be connected to, it returned
ProximityBluetoothStatusUndefined, which equates to 2, not 0. Now there
is a check for if(getSignal), in the corresponding locations, and
returns 0 if so.