This is intended as infrastructure to allow sepgsql to cooperate with
connection pooling software, by allowing the effective security label
to be set for each new connection.
KaiGai Kohei, reviewed by Yeb Havinga.
This is still pretty rough - among other things, the documentation
needs work, and the messages need a visit from the style police -
but this gets the basic framework in place.
KaiGai Kohei