A layer inside an instance can now override its resizing (hug, fill or
fixed, with min and max sizes; override group `resizing`) and its size.
They were refused, and imported ones were dropped at the first relayout.
Kept through rebuilds, undo, save, .fig and REST import, .fig export and
detach; reset per group and with Reset all changes. Position, constraints
and absolute or grid placement stay the main's.
bflatastic
6cdfe2ab8e