Excluding non-rare full names is not really possible because it makes
addresses with street names like 'main st' unsearchable. This tries to
leav all names in but refrain from ordering results by accuracy
when too many results are expected. This means that the DB will simply
get the first n results without any particular order.
Names of countries and states are exceedingly rare in the word count
but are very frequent in the address. A short name has the danger
of producing too many results.
Give a preference to left-right reading, i.e <postcode>,<address>
prefers a postcode search while <address>,<postcode> rather does
an address search.
Also exclude non-addressables, countries and state from results when a
postcode is contained in the query.
Search is now split into three functions: for free-text search,
for structured search and for search by category. Note that the
free-text search does not have as many hidden features like
coordinate search. Use the search parameters for that.
