Add dev-ml/opam-9999.

Also, a bug in opam-1.1.0.ebuild has been fixed.

Signed-off-by: OGINO Masanori <masanori.ogino@gmail.com>
Support CRuby 2.1.x.

Signed-off-by: OGINO Masanori <masanori.ogino@gmail.com>
Move opam from dev-ml to dev-util.

Signed-off-by: OGINO Masanori <masanori.ogino@gmail.com>