Test partition functions with legacy inheritance children, too

Consider only relations part of partition trees in partition functions

Make pg_partition_tree return no rows on unsupported and undefined objects

Tweak pg_partition_tree for undefined relations and unsupported relkinds

Add pg_partition_root to display top-most parent of a partition tree

Remove configure switch --disable-strong-random

Fix generation of padding message before encrypting Elgamal in pgcrypto

Improve comments and logs in do_pg_stop/start_backup