The only changes to this branch (from devel) is that the __slots__ statements in leoNodes.py have been commented out.
This will allow me (and anyone else) to check whether a recent bug is due to slots.
I'll keep the ekr-no-slots branch with devel. I'll delete ekr-no-slots branch before Leo 6.4. Its PR,
#2028, will always remain a draft.
Edward