Make full-text indexing faster by bypassing Active Record (wincent.dev, 7976609)

Well, not bypassing it entirely as we still go through connection.insert, but still, this yields a 10-fold speed-up. It is, however, still too slow for my liking; several seconds to index a largish (40+ KB) article in development mode. Even though production will likely be much faster I still don't think this is good enough.

In all likelihood I'll defer indexing and do it in a background process.

Signed-off-by: Greg Hurrell <greg@hurrell.net>