Apply the core parts of Dennis Bjorklund's patch to allow function

parameters to be declared with names.  pg_proc has a column to store
names, and CREATE FUNCTION can insert data into it, but that's all as
yet.  I need to do more work on the pg_dump and plpgsql portions of the
patch before committing those, but I thought I'd get the bulky changes
in before the tree drifts under me.
initdb forced due to pg_proc change.