Faster local start

 - The spark boot process can spend a lot of time figuring out what IP to bind the web interface to as it boots. I don't really care to make the web UI accessible, so I figure we can just bind it to 127.0.0.1 and prevent it from spending any time at all resolving the local host name or anything.
 - The kerberos auth which seems to be on by default in hadoop that causes the "Unable to load realm info from SCDynamicStore" message I'm sure we are all familiar with takes a little while to time out according to the debug log from spark. Adding these options to the `conf/java-opts` file which spark sources when it boots made the messages and wasted time go away. See http://stackoverflow.com/questions/7134723/hadoop-on-osx-unable-to-load-realm-info-from-scdynamicstore for where I found this out.

These two changes brought my starscream test run from 23 seconds to 3 seconds. Woo!

@tyro89 @honkfestival