Update to APR/native connector version 1.1.28 that includes a necessary fix for WebSocket and Servlet 3.1 non-blocking IO.
Also update the minimum required version to 1.1.28

git-svn-id: https://svn.apache.org/repos/asf/tomcat/tc7.0.x/trunk@1523649 13f79535-47bb-0310-9956-ffa450edef68