From pg_dump/pg_restore section (9.2 of the Todo page on the
PostgreSQL Wiki), is the following item
"Add comments to output indicating version of pg_dump and of the
database server"
simply asking for a change to the pg_dump header from:
--
-- PostgreSQL database dump
--
to something like:
-- PostgreSQL database dump
--
-- pg_dump version: 8.5devel
--
-- remote database version: 8.5devel (80500)
--
?