pgsql: Update contrib documention mentions to point to actual documenta

Update contrib documention mentions to point to actual documentation
sections, rather than just calling it "/contrib/module_name".

Also update pg_test_fsync build instructions now that it is in /contrib.

Branch
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master

Details
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http://git.postgresql.org/gitweb?p=postgresql.git;a=commitdiff;h=159e3d86292cfec2a2828f9f69ac7a6cb1be242d

Modified Files
--------------
doc/src/sgml/contrib-spi.sgml | 2 +-
doc/src/sgml/datatype.sgml | 6 +++---
doc/src/sgml/dblink.sgml | 2 +-
doc/src/sgml/diskusage.sgml | 3 +--
doc/src/sgml/high-availability.sgml | 8 ++++----
doc/src/sgml/installation.sgml | 10 +++++-----
doc/src/sgml/lo.sgml | 2 +-
doc/src/sgml/queries.sgml | 5 +++--
doc/src/sgml/recovery-config.sgml | 5 ++---
doc/src/sgml/ref/create_opclass.sgml | 4 ++--
doc/src/sgml/runtime.sgml | 5 ++---
doc/src/sgml/spi.sgml | 4 ++--
doc/src/sgml/storage.sgml | 4 ++--
doc/src/sgml/textsearch.sgml | 19 +++++++++----------
doc/src/sgml/trigger.sgml | 2 +-
doc/src/sgml/tsearch2.sgml | 20 ++++++++++----------
doc/src/sgml/vacuumlo.sgml | 2 +-
doc/src/sgml/wal.sgml | 8 ++++----
doc/src/sgml/xfunc.sgml | 5 +++--
19 files changed, 57 insertions(+), 59 deletions(-)