Remove hkit and do our own hcard parsing

Remove hkit and do our own hcard parsing

Parsing hcards for the data we need wasn't hard enough to justify using
hkit. It was dependent on a number of external systems (something to
run tidy), and only could handle XHTML.

We now parse HTML with the PHP dom libraries used elsewhere, and
scrape out our own hcards. Seems to work nicer and faster and most of
all works with Google Buzz profile URLs.