Mk/**ruby.mk: Switch from USE_RUBY=yes to USES=ruby

Switch from Mk/bsd.ruby.mk to Mk/Uses/ruby.mk

Notable changes are.

- Mk/bsd.ruby.mk is moved to Mk/Uses/ruby.mk.
- USE_RUBY=yes is replaced with USES=ruby.
- USE_RUBY_EXTCONF is replaced with USES=ruby:extconf.
- USE_RUBY_RDOC is replaced with USES=ruby:rdoc.
- USE_RUBY_SETUP is replaces with USES=ruby:setup.
- RUBY_NO_BUILD_DEPENDS and RUBY_NO_RUN_DEPENDS are replaced with
  USES=ruby:{build,none,run}.
- RUBY_REQUIRE isn't used anywhere, so removed.
- USES=gem now implies USES=ruby.

This is mainly the work of yasu@ at https://reviews.freebsd.org/D27863

I have just made some cosmetic changes and ran exp-run to test that the
tree is not in a BROKEN state.

Approved by:	portmgr
Differential Revision:	https://reviews.freebsd.org/D37925

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

Remove # $FreeBSD$ from Makefiles.

math/rubygem-numru-units: update to 1.9.0

PR:		224775
Approved by:	maintainer timeout (murashin@gfd-dennou.org, > 2 weeks)

math/rubygem-numru-units: remove unneeded USE_RAKE

Convert USES=gem:autoplist to USES=gem since autoplist is default

create USES=gem and update rubygem- ports to use it

Note that for now ports still have to have USE_RUBY=yes to use USES=gem

PR:		209041
Differential Revision:	https://reviews.freebsd.org/D6070

Set NO_ARCH for remaining rubygem-* ports with no arch dependent files

Obtained from:  DEVELOPER_MODE
With Hat:       ruby@

Sponsored by:   RideCharge Inc / Curb

Remove indefinite articles and trailing periods from COMMENT, plus minor
COMMENT typos and surrounding whitespace fixes. A few Makefiles where not
included as they contain Latin-1 characters that break the Phabricator
workflow. Category M.

CR:		D306
Approved by:	portmgr (bapt)

A class of units of physical quantities for Ruby.

This class covers most functionality of UNIDATA's UDUNITS Library, however,
with a more sophisticated handling of string expressions.

UDUNITS always decomposes units into the four base units and discards the
original string expressions. Therefore, 'hPa' always becomes '100
kg.m-1.sec-1', and 'day' always becomes '86400 sec'. On the other hand, this
library tries to keep the original expressions as much as possible by default,
while allowing partial to complete decompositions if needed.

WWW: http://www.gfd-dennou.org/arch/ruby/products/numru-units/

PR:		ports/190202
Submitted by:	Shin-ya MURAKAMI <murashin@gfd-dennou.org>