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 xmlns:xsd="http://www.w3.org/2001/XMLSchema" IEC_Channel="2" Name="py_ext_0"/>