Comment 9 for bug 1795241

Here you can find some screenshots showing why round edges are problematic, especially when connecting thick track to square pads:

* https://forum.kicad.info/t/changing-track-end-style-settings-in-pcbnew-square-end-traces-supported/2409

* https://forum.kicad.info/t/designing-high-current-traces-with-vias/7359

And some requests for the same feature:

* https://forum.kicad.info/t/wishlist-request-maybe-line-ends-are-always-round/5751

* https://www.allpcb.com/sns/KiCad/2016-08-08_1_10_518_How%2Bto%2Bchange%2Btrack%2Bend%2Bstyle%2Bsettings%2Bin%2BPcbnew~3/rpllst.html

BTW, out of nerdy interest, why are non round line ends problematic? Actually the question should be: why are non-round ends more problematic DRC-wise than tracing a polygon to connect two points?