Mocha Release 0.13.2

Fixes bug in stubbing of methods re-declared with different visibility.

Stubbing of methods re-declared with different visibility. Fixes issue #109. Thanks to Michael van Rooijen for reporting.
Add Mock#responds_like_instance_of. Fixes issue #119. Thanks to Simão Mata for the original pull request which formed the basis of this change.
Make Expectation#inspect less verbose and more useful. Fixes issue #122. Thanks to stackedsax for the suggestion.
Make unit tests more robust to changes in environment. Fixes issue #121. Thanks to Vít Ondruch for reporting.
Update README in an attempt to head Rails-related issues off at the pass.
Add a Gem badge () to provide a link to Mocha on Rubygems.
Make documentation example consistent with other examples.