filesystems: add new category for file systems and related utilities

The filesystems category houses file systems and file system utilities.
It is added mainly to turn the sysutils/fusefs-* pseudo-category into
a proper one, but is also useful for the sundry of other file systems
related ports found in the tree.

Ports that seem like they belong there are moved to the new category.
Two ports, sysutils/fusefs-funionfs and sysutils/fusefs-fusepak are
not moved as they currently don't fetch and don't have TIMESTAMP set
in their distinfo, but that is required to be able to push a rename
of the port by the pre-receive hook.

Approved by:	portmgr (rene)
Reviewed by:	mat
Pull Request:	https://github.com/freebsd/freebsd-ports/pull/302
PR:		281988

devel/tclvfs: Moved man to share/man

Approved by:    portmgr (blanket)

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.

devel: remove 'Created by' lines

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

  *  "Waitman Gobble" <uzimac@da3m0n8t3r.com>
  *  <jkoshy@FreeBSD.org>
  *  Aaron Dalton <aaron@FreeBSD.org>
  *  Aaron Dalton <aaron@daltons.ca>
  *  Aaron H. K. Diep <ahkdiep@gmail.com>
  *  Aaron Hurt <ahurt@anbcs.com>
  *  Abel Chow <abel_chow@yahoo.com>
  *  Adam McLaurin
  *  Adam Saponara <as@php.net>
  *  Adam Weinberger <adamw@FreeBSD.org>
  *  Ade Lovett <ade@FreeBSD.org>

Remove # $FreeBSD$ from Makefiles.

Update WWW: SF redirects to https://sourceforge.net/projects/<PROJECT_NAME>/

Add "tea" argument to USES=tcl to facilitate porting of TEA-based extensions.

Quoting https://tcl.tk/doc/tea:

"The Tcl Extension Architecture, or TEA, by John Ousterhout and others, is a
set of guidelines and techniques for the distribution, configuration,
compilation, and installation of Tcl extensions. TEA also provides a set of
utilities that operate accordingly. Many Tcl extensions leverage the TEA
utilities, which are designed to be easily customizable."

To facilitate the porting of TEA-based extensions, I have added the new "tea"
argument to USES=tcl. This argument prepares the autoconf environment by
setting GNU_CONFIGURE and sets some commonly used CONFIGURE_ARGS. Also, it
tries to figure out the correct extension name, sets TCL_PKG accordingly, and
adds it to PLIST_SUB.

I have modified a few ports to take advantage of this. More will come.

Remove ${PORTSDIR}/ from dependencies, categories d, e, f, and g.

With hat:	portmgr
Sponsored by:	Absolight

Cleanup plist

- Fix PLIST

Reported by:	QAT

- New port: devel/tclvfs

The TclVfs project aims to provide an extension to the Tcl language which
allows Virtual Filesystems to be built using Tcl scripts only. It is also a
repository of such Tcl-implemented filesystems (metakit, zip, ftp, tar, http,
webdav, namespace, url)

WWW: http://sourceforge.net/projects/tclvfs/