Improve rest project archetypes

Address some feedback about the REST/web project archetypes that I received during Summer 2014.  Specifically, pull the HTTP port for the server into a Maven/system property, add some javadocs to the servlet to make it more clear what the key/value application is all about, and add an index.html that contains some forms for interacting with the key/value application.  The changes have been replicated across the archetypes for all three projects.  These changes address issues #72, #75, and #77.