Use one of not-null unique keys to identify rows when the target table doesn't

have a primary key. Some of users want to use not-null unique keys rather than
primary keys because postgres doesn't support REINDEX PRIMARY KEY CONCURRENTLY.

- Support 9.1dev.
- Improve Makefile to use PGXS automatically.

lib/pgut/pgut-be.h

@@ -151,6 +151,12 @@ extern void tuplestore_putvalues(Tuplestorestate *state, TupleDesc tdesc,
 
 #endif
 
+#if PG_VERSION_NUM < 90100
+
+#define ATExecChangeOwner(relationOid, newOwnerId, recursing, lockmode) \
+	ATExecChangeOwner((relationOid), (newOwnerId), (recursing))
+#endif
+
 #if PG_VERSION_NUM < 80300
 #define RelationSetNewRelfilenode(rel, xid) \
 	setNewRelfilenode((rel))