Detect Lyo URI and correctly pass POST parameters

[berezovskyi]

This PR fixes two issues:

• supplying the Lyo base URI in the OAuth request context (see OAuthRequest(HttpServletRequest request, boolean detectLyoURI))
• properly passing POST parameters to the OAuth internals (see OAuthRequest.OAuthServletRequestWrapper class and OAuthService::doPostRequestToken where its intended use is shown)

This is a pretty major change and I am surprised how it worked before. Apparently, Wink had some extra behaviour that allowed for the input stream to be read multiple times.

[jadelkhoury]

I don't believe we have migrated lyo.server to Jax-rs 2.0. So maybe it's about time.
But as usual, with such large pull requests, I'd be happy to do a live review.

[berezovskyi]

Huh? https://github.com/eclipse/lyo.server/blob/master/pom.xml#L117

[jadelkhoury]

I take it back then :-)

[berezovskyi]

add comment why to do this

If the parameter data was sent in the request body, such as occurs with an HTTP POST request, then reading the body directly via getInputStream() or getReader() can interfere with the execution of this method.

https://docs.oracle.com/javaee/6/api/javax/servlet/ServletRequest.html#getParameter(java.lang.String)