Normalization and token computation are now done in the tokenizer.
The tokenizer keeps a cache to the hundred most used house numbers
to keep the numbers of calls to the database low.
Add a jsonb column to the placex and location_property_osmline tables
which can be used by the installed tokenizer as required. No other
part of the software will use or otherwise rely on this column.
Creating and populating the word table is now the responsibility
of the tokenizer.
The get_maxwordfreq() function has been replaced with a
simple template parameter to the SQL during function installation.
The number is taken from the parameter list in the database to
ensure that it is not changed after installation.
Adds a migration that initialises a legacy tokenizer for
an existing database. The migration is not active yet as
it will need completion when more functionality is added
to the legacy tokenizer.
Adds a 'admin --migrate' command that checks for the current
database version and runs any necessary migrations. Also
has migrations going back to 3.6.
