locale.c: Revamp initialization of parallel arrays

This new method eliminates a lot of #ifdef's in each of the array
initializations, consolidating all the array entries for a category
to be in a single group.  This facilitates ease of checking that things
are correct and the addition of new items.

A Factory pattern to generate all these could be used instead.  But I
don't know how to do that in cpp (I suppose some recursive #includes
would do it uglily), and I don't think it's worth it to do a regen
script.

There is a reason for the  apparently weird indentation, that future
commits will reveal.