Reuse getParsedBodyParam for determining method override in POST body.

[sander-bol]

Makes getMethod() internally use getParsedBodyParam() for determining the value of _METHOD in the request body, for purposes of overriding the body.

Question though: wouldn't this type of method-juggling be more appropriately implemented as a middleware rather than living in the core Request object logic, so it becomes an opt-in behaviour?

[coveralls]

Coverage increased (+0.06%) to 97.256% when pulling 2742aa0 on sbol-coolblue:improvement/parsedBodyParam into 2f29cc2 on slimphp:3.x.

[akrabat]

Yes. _METHOD will certainly be moved to middleware for 4.0

[akrabat]

Thanks.

[sander-bol]

You're welcome, and thanks for accepting my little contribution!