WIP Update capybara/capybara-webkit

Mainly involved disambiguating a few selectors as capybara 2 is more
strick and will raise an error if a selector matches more than one
element on the page, which is pretty sensible when you think about it.
In particular, the link finders (i.e matching based on link text) will
match both a link's text and a links title attribute, which means any
pages that have a textual link and an image linked with a title set to
the same text will get ambiguous matches.

WIP - Just the javascript tests failing now...