Forcibly close sockets when proxying HTTP servers with KeepAlives

The JDK assumes that we want the client side to hang on to the connection when proxying HTTP servers with KeepAlives turned on. The appliance does indeed close the socket after the proxying is finished, but the JDK will still hang on to it. So, convert code that uses URLConnection to use Apache Commons HTTP instead.

Also, kickstarting the jar upgrades. This release upgrades the clustering jar.