Add full-text indexing to sufia (from ScholarSphere)

refs gwu-libraries/gw-sufia#80
Lemme work on it a bit more.  I don't like that the full-text generator writes the jars directly to the hidden jetty dir because other generators don't function that way.  Thinking about having the generator write to a dir under version control, like solr_conf/, and then adding a new rake task (sufia:jetty:config ?) that copies these jars into the jetty dir.

Downside: the sufia repo gets a bit bigger with all those binaries checked in.
Upside: consistency with other generators and rake tasks.

Thoughts on this, @jcoyne @cam156 @dchandekstark @coblej ?