Updates to 81_simple_gui.py file
Updates to 81_simple_gui.py file

- Handling Connection, Device Discovery, Get Tags and updating tag(s) value(s) on separate threads
- Device Discovery and Get Tags are using separate instances of the PLC()
- Connection is using the GetPLCTime() function to confirm connection to the PLC
- Added option to select Micro800 PLC (tested only to pass the logic associated with it)
- Added showing pylogix version, generally to be used for troubleshooting purposes
- GUI changed with additional listboxes for connection and error messages
- GUI changed to introduce separate frames to keep controls better aligned when the window is maximized
- Introduced support for reading multiple tags as well (comma separated tags)
- Improved the handling of the right-click "Paste" feature
dmroeder/pylogix