pgsql: pg_dump, pg_upgrade: allow postgres/template1 tablespace moves

pg_dump, pg_upgrade: allow postgres/template1 tablespace moves

Modify pg_dump to restore postgres/template1 databases to non-default
tablespaces by switching out of the database to be moved, then switching
back.

Also, to fix potentially cases where the old/new tablespaces might not
match, fix pg_upgrade to process new/old tablespaces separately in all
cases.

Report by Marti Raudsepp

Patch by Marti Raudsepp, me

Backpatch through 9.0

Branch
------
REL9_3_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/ca445043e78ef7b2bbb911739f60b7a4726702b1

Modified Files
--------------
contrib/pg_upgrade/info.c | 20 +++++++++++++++++---
src/bin/pg_dump/pg_dumpall.c | 18 ++++++++++++++++++
2 files changed, 35 insertions(+), 3 deletions(-)