Removed copy of json2.js

JSON parsing facilities are built-in in modern browsers.
Use `on()` rather than `bind()`
Patched third-party libraries to remove `$.browser` calls

This is deprecated in newer jQuery versions and we need to get rid of them
to make the switch.
Upgrade jQuery and tipsy

Since tipsy depends on a newer jQuery, committing everything in a single
commit.

Note that to remove dangling tooltips, the `$.fn.tipsy.revalidate()`
function is called in a timely fashion.

Fixes #63 and fixes #25.