7.2 doc comments

There seems to be a typo in the GRANT documentation.
REFERENCES
To create of a table with a foreign key constraint, it is
necessary to have this privilege on the table with the primary
key.

I think you just want to remove "of".

I also found it odd that currval, nextval, and setval are covered in
the CREATE SEQUENCE and not in a section under functions. Even if the
main documentation for them stays in CREATE SEQUENCE, a reference to
them from the function documentation would be nice.