mod_http_oauth2: Reject duplicate form-urlencoded parameters Per RFC 6749 section 3.1 > Request and response parameters MUST NOT be included more than once. Thanks to OAuch for pointing out Also cleans up some of the icky behavior of formdecode(), like returning a string if no '=' is included.

--% conflicts: mod_bookmarks
module:log("info", "mod_bookmarks has been deprecated, now loading mod_bookmarks2")
module:depends("bookmarks2")