Saved matched records now unique

Save Match: Where a match record already exists, replace it  rather than
increase the weighting, so that there is now only one matching record in
the database for a given input value
Code matches: saved names now used first

The saved  matched names are now used to find the code first, before
that in the gazetteer, this means that the user can override the data in
the gazetteer (this needs to be reviewed)