added Person search for issue 57
added Person search results template for issue 57
added Person search option to templates for issue 57
added topic name search, issue 62
added topic search results template, issue 62
added topic search option, issue 62
added $regex query support for ArrayDocument
added way to get parent URL without a db query
record whether new Reply is for rec or post
protect against bad arxiv ID queries
added REST interfaces for regex query of comments, top-level Recs collection
templates for Post search results, and associated convenience methods
improved Rec page to show comments
add Comment search to all pages
added utilities for cleaning up the database