In commit b8d31d8534b ("Show ceilings for individual tissues") Robert
inadvertently broke the connection from dc_ceilings to red_ceilings and
also didn't correctly enable the checkbox for all_tissues when
calc_ceilings was already set in the preferences before the dialog was
created (and therefore the connection in the .ui file isn't run).
There's also a simplification / cleanup to the code deciding whether to
show all the tissues.
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
32d8051404