Add article about "Multiple HTTP connectors in Karaf"

git-svn-id: https://svn.apache.org/repos/asf/karaf/site/trunk@1444714 13f79535-47bb-0310-9956-ffa450edef68
Add article about "Load balancing with Apache Karaf Cellar, and mod_proxy_balancer"

git-svn-id: https://svn.apache.org/repos/asf/karaf/site/trunk@1444715 13f79535-47bb-0310-9956-ffa450edef68