Use the new proj4.js

This change updates ol3 to work with the new [proj4.js](https://github.com/proj4js/proj4js). Proj4js versions < 2.2 are no longer supported.
If the file is not compiled it will externs. We do that already for things that are in resources/example-behaviour.js.

But in this case I find it's good to have these function in the example's js file, because it gives more context to the reader, and thereby makes things easier to understand. So I'd rather keep them here.