Fix deprecation warnings.  Note that this commit means that CommonsHttpSender no longer tries to handle expect/continue or http 1.0/1.1 by itself; httpclient actually must do this work now.  Part of CONNECTORS-911

git-svn-id: https://svn.apache.org/repos/asf/manifoldcf/trunk@1579413 13f79535-47bb-0310-9956-ffa450edef68