Update of Ruby packages

[Takahiro Kambe <taca%NetBSD.org@localhost>]

Hi,

I'll start commiting ruby packages update.  Until my commiting
complete, most of ruby packages are temporary broken.


o General

* Ruby's patchlevel N reflect as "plN" instead of ".N" from Ruby 1.9.

        ruby18-base-1.8.7.302
        ruby19-base-1.9.2pl0

* RUBY_BUILD_RDOC and RUBY_BUILD_RI controls build of rdoc/ri.  But,
  currently ruby18-base and ruby19-base according to PKG_OPTION.

o lang/ruby/module.mk

* Default PKGNAME will be set to ${RUBY_PKGPREFIX}-${DISTNAME}.
* RUBY_HAS_ARCHLIB is deprecated.

o lang/ruby/replace.mk

* RUBY_ENCODING_ARG could be specify shbang line's additional option,
  specifying character encoding of scripts.

o Gem

* misc/rubygems/rubygem.mk moved to lang/ruby/gem.mk.
* misc/rubygems and devel/rake install gem/rake command as gem18/rake18
  since ruby19-base install these commands as gem19/rake19.
* GEM_DOCDIR and GEM_LIBDIR has changed to relative path against PREFIX.
* GEM_BUILD's default has changed from rake to gemspec.  Now, most of
  rubygem based pacakges are installed via gem command.
* USE_RAKE controls the needs of the rake command.

Best regards.

-- 
Takahiro Kambe <taca%NetBSD.org@localhost>/<taca%back-street.net@localhost>