Source maps for jQuery 1.9.0.

As of release 1.9.0, jQuery comes with source maps. This lets point to the minified file in both development and production, and still get sane stack traces if something bad happens. Source maps are currently supported in the developer tools that ship with Firefox and Chrome.

From a CDN perspective, it's nice to know that the source maps should only get downloaded if the dev tools are activated, so regular users won't be downloading the big *.map file or the un-minified .js file.

I downloaded the source map from the official jQuery site.
http://code.jquery.com/jquery-1.9.0.min.map

Then I replaced "jquery-1.9.0" with "jquery" in 2 places in the file.

Fortunately, jquery.min.js correctly points to jquery.min.map as its source map (search for `//@ sourceMappingURL=` to confirm) so I didn't have to modify it.