pg_upgrade docs:  give tips on automation

Document that post-upgrade steps are likely to be the same for all
clusters with the same DDL/schemas;  this should help automated
upgrades.
Use pg_dump's --quote-all-identifiers option in pg_upgrade.

This helps guard against changes in the set of reserved keywords from
one version to another.  In theory it should only be an issue if we
de-reserve a keyword in a newer release, since that can create the type
of problem shown in bug #8128.

Back-patch to 9.1 where the --quote-all-identifiers option was added.
Remove make_keywords

It is not used anymore.
Update key words table for 9.3
Fix management of fn_extra caching during repeated GiST index scans.

Commit d22a09dc70f9830fa78c1cd1a3a453e4e473d354 introduced official support
for GiST consistentFns that want to cache data using the FmgrInfo fn_extra
pointer: the idea was to preserve the cached values across gistrescan(),
whereas formerly they'd been leaked.  However, there was an oversight in
that, namely that multiple scan keys might reference the same column's
consistentFn; the code would result in propagating the same cache value
into multiple scan keys, resulting in crashes or wrong answers.  Use a
separate array instead to ensure that each scan key keeps its own state.

Per bug #8143 from Joel Roller.  Back-patch to 9.2 where the bug was
introduced.