Refactored HTTP message parsing APIs

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk@1641927 13f79535-47bb-0310-9956-ffa450edef68
Eliminated BufferInfo interface

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk@1641928 13f79535-47bb-0310-9956-ffa450edef68
Missing @Override annotations

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk@1641929 13f79535-47bb-0310-9956-ffa450edef68
RFC 7230: it is legal for any request method to enclose an entity; revised message delineation logic; removes HttpEntityEnclosingRequest interface; fixes HTTPCORE-318, HTTPCORE-380

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk@1641930 13f79535-47bb-0310-9956-ffa450edef68