deprecate "usage" function?

[John W. Eaton]

Octave has both "print_usage" and "usage".  We should be using
"print_usage" internally in Octave because it extracts the usage
message directly from the doc string so there can't be any difference
between the function documentation and the usage message that is
displayed when functions are called incorrectly.  So I don't see any
particular need for the "usage" function.  Is there any objection to
deprecating the "usage" function and eventually removing it from
Octave?

jwe