minor cleanup
gui: allow expressions in mesh size
gui: fix CLI for firefox (Thanks Raffaele Pellicelli)
start to unify relaxStep with normal run
relax uses same runWhile as everything else
panic on UserErr does not crash GUI
gui: don't disable controls on busy
GUI: explicit break() before run/steps/relax
no more crash when rapidly clicking run/steps/relax
cleanup error logging
gui: continously update on range slider move
gui: fade smoothly on disconnect
gui: max 1 pending request, refresh everything after dropped packet