Search within fields

[heikkilevanto]

As commented in #86, it would be nice to be able to search only in beer names, breweries, locations, etc.

Add a new url argument, something like '...&sf=Beer', and modify the search logic to handle that.

Not very urgent.

[heikkilevanto]

Easier to do now with the new data model, when all fields are in $rec, and can be selected with $rec->{$fieldname}