Geocoder AJAX Prepopulate

Extension above the Geocoder module, so that the editor can:
* give an address in a field (for example an Address field),
* click on an AJAX button that geocodes this address to prefill a geofield (through Geocoder),
* check the calculated coordinates (through a Geofield Map widget for example),
* change them manually if the geocoding was wrong or not precise enough (through Geofield Map for example).

The main difference with the basic Geocoder feature is that geocoding is triggered manually by the editor on the form, and not on save. This allows the editor to see the geocoding result and to correct it, or even to give the coordinates directly, without using the geocoding.

It's a bit like the search feature provided by the Geofield Map module, but the search is based on a real Drupal entity field, corresponding to an address which will be stored, generally to be displayed on the website.

Use 1.x for Geocoder 2.x, 2.x/3.x for Geocoder 3.x/4.x