Fix for the Zend\Filter\Encrypt and Zend\Filter\Compress adapters
Merge pull request #181 from ezimuel/fix/input-filter

Fix for the Zend\Filter\Encrypt and Zend\Filter\Compress adapters
[#181] Refactor to standalone listener class

Per discussion with @ezimuel, refactored listener to its own class. In doing so,
also altered it to operate inside the content negotiation -> content validation
workflow, pulling and operating on the data discovered by content negotiation.

Also wrote unit tests for the listener to ensure the expected behavior is
honored for all possible request scenarios.
Merge branch 'hotfix/181'

Close #181
Fixes #163