move word table and normalisation SQL into tokenizer

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.

lib-sql/functions.sql

@@ -1,5 +1,4 @@
 {% include('functions/utils.sql') %}
-{% include('functions/normalization.sql') %}
 {% include('functions/ranking.sql') %}
 {% include('functions/importance.sql') %}
 {% include('functions/address_lookup.sql') %}