Adding new configuration option "listenLocalOnly"

- This patch adds the configuration-option "listenLocalOnly" for both
  the indexer and the searcher. Sometimes it could be useful to
  (atleast in our environment) to restrict the the access to these
  "daemeons". Instead of complicating things with iptables (or other
  tools) I think it could be a good idea to have an option for this,
  hence this patch.

  I've tried it out and it seems to work as expected. Thoughts ?

Change-Id: Id848bbdd4aa1241065e766487d2b516d29b3ed9e