Cleanups

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk@1598051 13f79535-47bb-0310-9956-ffa450edef68
Use ExceptionLogger in HttpAsyncService, HttpAsyncRequester and HttpAsyncRequestExecutor

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk@1598052 13f79535-47bb-0310-9956-ffa450edef68
Slightly better synchronization

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk@1598053 13f79535-47bb-0310-9956-ffa450edef68
 Bootstrap for embedded server based on non-blocking I/O

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk@1598055 13f79535-47bb-0310-9956-ffa450edef68