Initial steps to make site fallback to no-js

Root page and project_items_index page work without js (loading the
entire page rather than using Ajax).

Also cuts down on database calls to find "Favorites", and reduces a
long SQL query that added a pair of virtual columns to the projects it
returned (which I was quite fond of, *sigh*) to a much simpler chain of
ActiveRecord methods. A pair of attr_accessor macros add those virtual
columns back to the projects.

N.B. the new query requires that a before_filter callback that assigns
@items be executed before the query (which is also a before_filter
called get_detailed_project_info).