Performance optimization: use bulk ByteBuffer#put method instead of single byte ByteBuffer#put

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpcore/branches/4.2.x@1477535 13f79535-47bb-0310-9956-ffa450edef68
Request output if request execution handler is not done (has subsequent requests)

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpcore/branches/4.2.x@1477537 13f79535-47bb-0310-9956-ffa450edef68