Upgrade to Solr 4.3.0

* Update match version to LUCENE_43

* Change dir factory to NRTCachingDirectoryFactory, it has
  optimization for smaller files and is the default in latest example.

* Switch to log4j for logging.  Solr now includes log4j in the example
  app so I switched to using that which required some change in how
  the Solr process is started.  In order to get `log4j.properties` on
  the classpath need to not use the `-jar` option and instead
  explicitly invoke Jetty's main entry.
Remove JSON query response writer

Remove this query response writer as it is causing JSON data to be
returned with text/plain content-type.
Remove unused lib dirs from config
Don't include test keystore with custom Solr package
Fix broken distclean
Merge pull request #122 from basho/rz-solr-430

Upgrade to Solr 4.3.0