Deprecated uitable properties

[Rik]

11/22/18

Support for uitable graphic widgets was added recently (Nov. 16th).  The
implementation has support for three graphics properties--"keypressfcn",
"keyreleasefcn", and "rearrangeablecolumns""--which Matlab no longer seems
to offer.

Should Octave implement these properties in the 5.0 release, but
immediately schedule them for deprecation in version 7?  Or, since we have
never offered uitables before, should we just remove those properties now
so the first version Octave offers is compatible with Matlab?

--Rik