Retirement of Ruby 1.9.3 and switch default Ruby to 2.1

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

Hi,

Ruby 1.9.3 had become EOL 23th February 2015 and Ruby 2.0 has good
compatibility with it.  So, we can safely retire ruby193-base and
related pacakges.  Is there any opinion?

And I would change default version of Ruby to 2.1.

    * Ruby 2.0.0 is in security maintenance phase (no active update)
      and it will become EOL on 24th February 2016.
    * A few ruby package are not support Ruby 2.2 yet.

Is there any comment?

-- 
Takahiro Kambe <taca%NetBSD.org@localhost>