CONST_BasePath is split into separate configuration variables
for binaries, libraries and data. These variables as well as
the installation path are now set in the executable directly and
no longer configurable via project settings.
This is the first step towards an installable software. The
executables should know per installation where to find their
necessary data to execute. Project configuration needs to be
restricted to settings that really concern the specific Nominatim
installation.
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.
Switch from an recursive algorithm for computing the word sets
to an iterative one that benefits from caching intermediate
results. This considerably reduces the amount of memory needed,
so that the depth restriction can be dropped. To ensure that
the number of word sets remains manageable, only sets up to
a certain length are accepted and only a certain number of
total word sets. If word sets need to be dropped, we drop
the ones with more words per word set first.
To further reduce the number of potential word sets, the valid
tokens are looked up first and then only word sets containing
valid tokens are computed.
Fixes#1403, #1404 and #654.
