NIO connection pool was found to stop processing of pending requests prematurely (for instance, upon a request timeout) which could lead to unnecessary delays in connection allocation. When processing the next pending request the pool should continue iterating over pending requests until one of two conditions is met: a pending request has been successfully handled by either allocating a persistent connection or by requesting a new connection or the queue has been fully exhausted.

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpcore/branches/4.2.x@1489445 13f79535-47bb-0310-9956-ffa450edef68