Add pgstattuple2 function to allow block sampling in order to
estimate live tuples, dead tuples and free spaces in the specified
table.
Merge branch 'master' into pgstattuple2
Merge branch 'master' into pgstattuple2
Merge branch 'master' into pgstattuple2
Merge branch 'master' into pgstattuple2
Fix pgstattuple2() to allow running only on a >3000 blocks table.
Merge branch 'master' into pgstattuple2
Merge branch 'master' into pgstattuple2

Conflicts:
	contrib/pgstattuple/Makefile
	contrib/pgstattuple/pgstattuple--1.1--1.2.sql
	contrib/pgstattuple/pgstattuple--1.2.sql
Merge remote branch 'remotes/postgres2/pgstattuple2' into pgstattuple2
Fix to remove a duplicated declaration.
Merge remote branch 'remotes/postgres2/pgstattuple2' into pgstattuple2
Merge branch 'master' into pgstattuple2
Merge remote branch 'origin/pgstattuple2'