sci-libs/symmetrica: new C library for representation theory and more.

sci-libs/symmetrica: new C library for representation theory and more.

This package has been forked under the SageMath umbrella, and the
build system has been overhauled to the point that maintaining it will
not be a punishment. The new v3.0.1 is the first release of the fork
if you pretend that v3.0.0 never happened (I forgot to include the
documentation in the release tarball).

The upstream SageMath project can detect and use the system copy of
symmetrica now, so this will allow Gentoo users of SageMath to avoid
pointless rebuilds of symmetrica.

Closes: https://bugs.gentoo.org/232014
Package-Manager: Portage-2.3.79, Repoman-2.3.16
Signed-off-by: Michael Orlitzky <mjo@gentoo.org>