add progress bar to status bar

It can be used to display progress during program upload.
To use it call ShowPLCProgress (like ShowPLCProgress("transfered",
10)) in your PLCObject implementation.

[TOPOLOGY]
NetName=None
Nodes=0x01
Node2Present=0x01
Node2Name=SlaveNode
Node2DCFName=Slave_0_0.eds
EDSBaseName=eds