Log Message:
Update ruby-hashery to 2.1.0.

== 2.1.0 / 2012-11-24

The major change of the 2.1 release is to switch over to `Hash#fetch`
as the fundamental CRUD read method inplace of the previous `#read` core
extension (an alias of `#[]`). This is a pretty fundamental change which
required modification of a number of classes. So please do extra-diligence
and file an issue if you experience any problems.

In addition, the Hash#read core extension has been renamed to Hash#retrieve
to avoid any possible confusion with IO objects. This release also fixes
a couple of issues with 1.8 compatibility and makes a few other small
enhancements.

Changes:

* Rename Hash#read to Hash#retrieve.
* Deprecate `Dictionary.alpha` in favor of `Dictionary.alphabetic`.
* Add support for block argument in Dictionary#order_by_key and #order_by_value.
* Fix OpenHash issues with Ruby 1.8.x compatibility.
* OpenHash methods are opened up via `protected` instead of `private`.
* Change OpenCascade to auto-create the subclass when inherited.