Multi-word partial terms had an undue advantage over separate partial
terms because they only need to pay the penalty once. This changes
the behaviour by setting the penalty according to the number of
words in the token. This should get rid of search interpretations
with low chance of matching.
This also fixes handling of exact term matching. We now match against
all exact terms of the query, not just a couple of them collected
while building the interpretations.
Also adds a penalty to very short postcodes.
The NearPoint is actually common to all SearchDescriptions
and there is other context data as well. like viewbox, that
needs to be available to the search object but is common.
