gui mutex and cleanup
fix one gui race
fix keepalive race
script: fix can not call error message (Thanks Mathias Helsen)
fix Init() duplicate dot import
remove unused script.Cnst() and fix use in excitation
remove obsolete script.Pure
script: Expr has explicit Child()
demagkernel xyz fix for 2D
gui: remove Span & Button varargs
fix omf/ovf xyz format
rm empty mumax3-convert/dump.go