Reset OSM Geocoder to the vendor version

[eliemichel]

Control.OSMGeocoder.js has been customized, but it is hence almost impossible to update it.

We should keep its vendor version clean and adapt it through another script.

[Phyks]

Upstream does not seem to be maintained anymore. Shouldn't we just fork upstream and include it in our code?

[eliemichel]

We could also drop it, I don't know since I did not look at what it is used for yet.

Anyway, even if we fork it, there should not be VelibFxos dependent code in it as it is now, so it still needs to be cleaned up.