Overhaul new function ismembertol (bug #56735, patch #10355). * scripts/set/ismembertol.m: Add one line description to top of help text. Change wording in documentation string. Use table for documentation of property- value pairs. Adapt to Octave coding style. Use more specific error messages in input validation. Allow lower-case property names. Use transpose operator instead of ctranspose operator. Break some very long lines. Remove some debug output. Use spaces instead of tabs for indentation. Remove whitespace from end of lines. Update self tests. * scripts/set/ismember.m: Add cross-reference to new function. * scripts/set/module.mk: Add new function to build system. * doc/interpreter/set.txi: Add help text of new function to documentation. * etc/NEWS.9.md: Add new function to list.

To cite GNU Octave in publications use:

  John W. Eaton, David Bateman, Søren Hauberg, Rik Wehbring (2023).
  GNU Octave version 8.2.0 manual: a high-level interactive language for
  numerical computations.
  URL https://www.gnu.org/software/octave/doc/v8.2.0/

A BibTeX entry for LaTeX users is:

  @manual{,
    title     = {{GNU Octave} version 8.2.0 manual: a high-level interactive language for numerical computations},
    author    = {John W. Eaton and David Bateman and S{\o}ren Hauberg and Rik Wehbring},
    year      = {2023},
    url       = {https://www.gnu.org/software/octave/doc/v8.2.0/},
  }

We have invested a lot of time and effort in creating GNU Octave, please
cite it when using it.  See also 'citation pkgname' for citing Octave
packages.