Log Message:
Update ruby-rspec-mocks to 2.12.1.

### 2.12.1 / 2012-12-21
[full changelog](http://github.com/rspec/rspec-mocks/compare/v2.12.0...v2.12.1)

Bug fixes

* Fix `any_instance` to support `and_call_original`.
  (Myron Marston)
* Properly restore stubbed aliased methods on rubies
  that report the incorrect owner (Myron Marston and Andy Lindeman).