Some dive-editing undo commands have trivial setter and getter
functions: they simply read and write a struct dive member.
Autogenerate these in a template to which we pass a pointer
to member as template argument.
For the invalid-flag we have to turn the edit command from int
to bool, since that is how the flag is store in the dive struct.
Sadly, quite a number of the setters do funky things and we
cannot autogenerate them.
Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
ea813938a8