Import of Ruby 2.2.1 and change of PKGPATH of Ruby 2.1.5

[Takahiro Kambe <taca%back-street.net@localhost>]

Hi,

I'm preparing importing Ruby 2.2.1 to pkgsrc.

Along with it, I will add some modifications to current Ruby 2.1.5.

    RUBY_PKGPREFIX from "ruby215" to "ruby21"
    RUBY_VER_DIR from "2.1.5" to "2.1.0" ("${RUBY_VERSION}" to "${RUBY_API_VERSION}"

So, binari packages have "ruby21-" instead of "ruby215-".


Background

	From Ruby 2.1.0, Ruby stop releasing "patch release" but
	"teeny version release".

	ABI is kept among these teeny version releases.

	So, Ruby 2.1.x should have the same RUBY_PKGPREFIX and version
	in include/library directory.

Best regards.

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