Replaced buddylist geolocation link with OSM minimap based on Leaflet.

This changeset replaces the Google Maps link in the buddy PEP info popup with a link that opens an integrated mini map based on OpenStreetMap and leaflet as described in issue #345.

I have not touched the icon showing the local user's position; I intend to implement an overview map of all contacts first and then have that icon point there. I think it would also be good if one could set one's location from this map.

The current change looks like this:

![Screenshot](http://shore.naturalnet.de/~nik/screen-jappix-geoloc-mini.png)