When changing something in the default configuration of the sanatizers
that refers to an analyzer that is not yet loaded, there shouldn't be
any errors.
This gives the analyzer more flexibility in choosing the normalized
form. In particular, an analyzer creating different variants can choose
the variant that will be used as the canonical form.
Implements per-name choice of analyzer. If a non-default
analyzer is choosen, then the 'word' identifier is extended
with the name of the ana;yzer, so that we still have unique
items.
