Mk/**tex.mk: Convert bsd.tex.mk to USES=tex

- Update all the consumers to use USES=tex
- USE_TEX=yes is the old way of writing USES=tex which has been removed
  and replaced in all ports
- Almost all of the USE_TEX features remains unchanged
- Some consumers had the same variables defined both in the mk
  infrastructure and also in the ports which have been removed from the
  ports as those are redundant.

In case any of the consumers are failing to build please make sure that
the nexessary USES=tex is there. Unlike previous USE_TEX=yes will no
longer load the required VARS for tex and related dependencies.

Reviewed by:	portmgr
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.

cad: remove 'Created by' lines

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

  *  AMAKAWA Shuhei <amakawa@jp.FreeBSD.org>
  *  Alexey Dokuchaev <danfe@FreeBSD.org>
  *  Anders Andersson <anders@hack.org>
  *  Bruce M Simpson <bms@FreeBSD.org>
  *  Christoph Moench-Tegeder <cmt@FreeBSD.org>
  *  David Yeske <dyeske@gmail.com>
  *  Diane Bruce <db@db.net>
  *  Joachim Strombergson <watchman@ludd.ltu.se>
  *  Johnny Sorocil <jsorocil@gmail.com>
  *  Julian Jenkins <kaveman@magna.com.au>
  *  Marc Fonvieille <blackend@FreeBSD.org>

cad/opencascade740: Remove TBB dependency

PR:		262209
Reported by:	Thibault Payet <monwarez@mailoo.org>

Update CONFLICTS definitions in categories a* to c*

Update the CONFLICTS definitions of ports in the following categories:

- accessibility
- archivers
- audio
- benchmarks
- biology
- cad
- chinese
- comms
- converters

An attempt has been made to use generic conflicts patterns that do not
have to be updated whenever a new version of a conflicting port is
added to the ports system.

There is a misunderstanding that the port being built/installed has to
be omitted from the conflicts pattern. This is not true - the port
being built is implicitly non-conflicting due to logic in bsd.port.mk.

Approved by:	portmgr (implicit)

cad/opencascade740: Resurrect cad/opencascade @ version 7.4.0

This is needed for science/chrono.