ParseRequestBody: like ContentTypes, but without breaking getBody()

supplementing https://github.com/codeguy/Slim-Middleware/pull/2 

This feature branch would contain the variant where ContentTypes is deprecated and replaced by ParseRequestBody.

This solution is not pretty, a programmer would need to write
$env = $app->environment();
$env['slim.input_parsed']

On the other hand, sneaking a method into the request object, so it would be possible to
$app->request->getBodyParsed()
would result in complex code more likely to contain bugs, and will sure enough cause some other programmer considerable headache sometime in the future.
That's why I left it that way.


In the end, it MAY be best to just do nothing and discard both of my pull requests. But first I wanted to discuss the matter with you.


regards,

Max