Solves #258. Added auto_convert config parameter
feature #278 Solves #258. Added auto_convert config parameter (mmoreram)

This PR was squashed before being merged into the 3.0.x-dev branch (closes #278).

Discussion
----------

Solves #258. Added auto_convert config parameter

* Added config parameter to disable auto convert
* By default this flag is set to true, avoiding BC break.
* If true, automatic ParamConverter applying in parameters without annotation
  definition is avoided

Commits
-------

e9ccbc6 Solves #258. Added auto_convert config parameter
tweaked previous merge
fixed CS on a test file
added some unit tests for the auto-convert flag