Load JSON with a callback file, and improve the location XML to JSON conversion.

Hi again!

I made a couple more tweaks. First off, I made it so a callback file isn't needed anymore to get the JSON. Now, using `$.getJSON`, the JSON is retrieved, then executed. This means that we can get rid of all the callback files, which makes the repo a bit smaller. (if there was some other reason for having the callback files, let me know)

As well, I improved the location converter, so that it now uses the `async` module (you'll want to run `npm install` to install the module, since I also added a `package.json`), which allows for queues. The queue does the same as what there was before, but can now execute 4 tasks at once. This, along with not having to compile callback files, means that it's faster! :boom: