OPTRArcShape's width is already defined in TRAbstractLineShape

[hernanmd]

Also accessors are defined in TRAbstractLineShape newest versions.

[JanBliznicenko]

I am working on updating, fixing and improving OpenPonk for our cases and decided to use my own Pharo 7 fixes I had prepared for a long time (just as you had).
Current master of OpenPonk is usable enough on Pharo 7 and 8. but, of course, is not usable on Pharo 6 anymore. After I finish few fixes and planned improvements and check once again everything works as it should, I will make another tag/release, probably named 2.0.0 (yes, I know, it should be more like 0.0.2 :) but the major version increase is there to make sure no 1.x dependencies would load this version which does not work on Pharo 6 anymore)