Added support for bower

Hi guys,

I've added bower support to your project. As your project has a couple of dependencies I found it useful. It means the lib directory can be deleted. It should make it easier to test all the examples with the latest versions of leaflet and proj4 in the future too. 

The downside is that anyone wanting to work with your source has to run "bower install" before they look at your tests or examples. But we're pretty used to the process with serverside javascript code downloaded from github requireing an npm install to get the dependencies.

If you want to pull it in you'll want to delete line 21 in the bower.json to make the project public. Didn't want there to be a risk that my fork became the one registered with bower.

Regards

Tom