HTTPCORE-331: BasicFuture no longer executes notification callbacks inside a synchronized block

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpcore/branches/4.2.x@1435144 13f79535-47bb-0310-9956-ffa450edef68
HTTPCORE-331: BasicFuture no longer executes notification callbacks inside a synchronized block (cleanup)

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpcore/branches/4.2.x@1435147 13f79535-47bb-0310-9956-ffa450edef68
HTTPCORE-331: fixed possible race condition in case of an exceptional condition (such as an I/O error)

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpcore/branches/4.2.x@1435160 13f79535-47bb-0310-9956-ffa450edef68