Add support for generating output sheets using the Freemarker templating engine
* Full FreeMarker character export integration test
* Move a few representative character tests to use freemarker
* Allow pcstring to be used as a function as well as a directive.
Issue#: CODE-2312


git-svn-id: svn+ssh://svn.code.sf.net/p/pcgen/code/Trunk@22647 ef53c05b-3124-4d59-ae7d-fe3273f42be7