Unit tests for MainClientExec

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk@1511445 13f79535-47bb-0310-9956-ffa450edef68
Cleaned up HttpRoute

git-svn-id: https://svn.apache.org/repos/asf/httpcomponents/httpclient/trunk@1511446 13f79535-47bb-0310-9956-ffa450edef68