GraphicCommons.py : rewrote Wire.Setpoints.
- trying to make it fix diagonal wires,
- wasn't clear what was intended before, so made it clear :
- duplicate point removal
- segment merging (only if asked)
- remove corners made of opposite direction segments

<?xml version="1.0" encoding="UTF-8"?>
<BaseParams Name="svgui" IEC_Channel="0"/>