Chile local flavor: New form select field: CLCommuneSelect

Included a list of commune as choices in localflavor/cl/cl_communes
Included a select field in localflavor/cl/forms.py

Also included a dict with the name of the communes mapping to the region
they belong to in localflavor/cl/cl_regions, in case someone wants to
validate the correspondence of the commune in the region.

Finnaly, changed the localflavor/cl/forms.py file to fit every line in
80 characters
Each tuple should have its second member translatable. On the other hand the first member is only stored in the database so it does not need to be a full name complete with accents (though it is up to you to decide if you want to change  it).