Provide Information to JVM tuning

[coderoshi]

With yokozuna, we're going to have to guide users in some basic way to appropriate documentation, tools and other resources for monitoring and tuning their solr JVM process. They should be able to find common problems with solutions, or where/how to investigate their own node configurations.

• http://docs.oracle.com/javase/7/docs/technotes/guides/management/jconsole.html
• https://wiki.apache.org/solr/SolrPerformanceFactors
• https://wiki.apache.org/solr/SolrPerformanceProblems

[lucperkins]

I added some links to the YZ ops doc in commit f69bdb3. I'm closing for now, but will give links to Solr info some more TLC later.