math/pari: update 2.15.5 → 2.17.1

math/sympow: upgrade to 2.023.7

bsd.sites.mk: Update all ports using USE_GITLAB

Replace GL_COMMIT by GL_TAGNAME in all ports. The new GL_TAGNAME is
backwards-compatible (accepting any commit hash as before), but also
understands an actual tag name. Moving to tag names where appropriate is
left to individual ports' maintainers.

Approved by:		portmgr (tcberner, mentor)
Differential Revision:	https://reviews.freebsd.org/D37077

math/pari: Update 2.13.4 -> 2.15.0

Reported by:	portscout

Remove WWW entries moved into port Makefiles

Commit b7f05445c00f has added WWW entries to port Makefiles based on
WWW: lines in pkg-descr files.

This commit removes the WWW: lines of moved-over URLs from these
pkg-descr files.

Approved by:		portmgr (tcberner)

Add WWW entries to port Makefiles

It has been common practice to have one or more URLs at the end of the
ports' pkg-descr files, one per line and prefixed with "WWW:". These
URLs should point at a project website or other relevant resources.

Access to these URLs required processing of the pkg-descr files, and
they have often become stale over time. If more than one such URL was
present in a pkg-descr file, only the first one was tarnsfered into
the port INDEX, but for many ports only the last line did contain the
port specific URL to further information.

There have been several proposals to make a project URL available as
a macro in the ports' Makefiles, over time.

math: remove 'Created by' lines

A big Thank You to the original contributors of these ports:

  *  Aaron Dalton <aaron@FreeBSD.org>
  *  Aaron Dalton <aaron@daltons.ca>
  *  Alessando Sagratini <ale_sagra@hotmail.com>
  *  Alex Dupre <ale@FreeBSD.org>
  *  Alexey Dokuchaev <danfe@FreeBSD.org>
  *  Amarendra Godbole <amarendra.godbole@gmail.com>
  *  Anders Nordby <anders@FreeBSD.org>
  *  Andreas Fehlner (fehlner@gmx.de)
  *  Andrew L. Neporada <andrew@chg.ru>
  *  Andrey <gugu@zoo.rambler.ru>
  *  Andrey Zakhvatov

math/sympow: respect user-provided CFLAGS

And also resolve a warning when building data files.

Regenerate all distfiles using gitlab as source.

This regeneration is required as the new gitlab version changed
the address and the directory the source files can be downloaded.

This commit also applies some small fixes to make sure all ports using
gitlab are buildable.

Reviewed by:	mat
Approved by:	portmgr
Differential Revision:	https://reviews.freebsd.org/D29628

Remove # $FreeBSD$ from Makefiles.

math/pari: Update 2.11.4 -> 2.13.0

Bump 15 depending ports.

Reported by:	portscout

math/sympow: Fix build by setting HOME env var to WRKDIR.

Add compiler:c++11-lang to USES to fix build on GCC-based systems:

  Error: moving to 21st century and adding GNU feature are denied

While here, pet portlint (rearrange lines).

Approved by:	portmgr (tier-2 blanket)

Adding sypow, a mathematical program to compute special values of symmetric
power elliptic curve L-functions; it can compute up to about 64 digits of
precision.

It was bundled with SageMath, and now will be used as a dependency.