- Break a build dependency loop in the server packages that led to
bootstrap problems.

- Update to version 9.3.18:
* https://www.postgresql.org/docs/9.3/static/release-9-3-18.html
* Show foreign tables in information_schema.table_privileges
view.
* Clean up handling of a fatal exit (e.g., due to receipt of
SIGTERM) that occurs while trying to execute a ROLLBACK of a
failed transaction.
* Remove assertion that could trigger during a fatal exit.
* Correctly identify columns that are of a range type or domain
type over a composite type or domain type being searched for.
* Fix crash in pg_restore when using parallel mode and using a
list file to select a subset of items to restore.
* Change ecpg's parser to allow RETURNING clauses without
attached C variables.