Modbus and Bacnet websettings : Rename variables and functions to avoid name collisions.

Websettings for modbus and bacnet are now passed to runtime as python files loaded (execfile) at init of PLCObject with the same globals.
Because if this, same names used in previously different modules now colide.

<?xml version='1.0' encoding='utf-8'?>
<BACnetServerNode xmlns:xsd="http://www.w3.org/2001/XMLSchema" UDP_Port_Number="47808" BACnet_Device_ID="3" BACnet_Communication_Control_Password=" " BACnet_Device_Location="Beremiz lab" Network_Interface="virbr0"/>