SOLR-3854: Allows the test harness to perform two-way SSL handshakes, the two-way SSL will now be randomly selected during test runs. Also, cleaned up some of the code by breaking out the SSLConfig into a separate class. Also try and address failing the statics retained check.

git-svn-id: https://svn.apache.org/repos/asf/lucene/dev/trunk@1566515 13f79535-47bb-0310-9956-ffa450edef68