Use the term "radix tree" instead of "suffix tree" for SP-GiST text opclass.

What we have implemented is a radix tree (or a radix trie or a patricia
trie), but the docs and code comments incorrectly called it a "suffix tree".

Alexander Korotkov
Fix walsender failure at promotion.

If a standby server has a cascading standby server connected to it, it's
possible that WAL has already been sent up to the next WAL page boundary,
splitting a WAL record in the middle, when the first standby server is
promoted. Don't throw an assertion failure or error in walsender if that
happens.

Also, fix a variant of the same bug in pg_receivexlog: if it had already
received WAL on previous timeline up to a segment boundary, when the
upstream standby server is promoted so that the timeline switch record falls
on the previous segment, pg_receivexlog would miss the segment containing
the timeline switch. To fix that, have walsender send the position of the
timeline switch at end-of-streaming, in addition to the next timeline's ID.
It was previously assumed that the switch happened exactly where the
streaming stopped.

Note: this is an incompatible change in the streaming protocol. You might
get an error if you try to stream over timeline switches, if the client is
running 9.3beta1 and the server is more recent. It should be fine after a
reconnect, however.

Reported by Fujii Masao.
The data structure used in unaccent is a trie, not suffix tree.

Fix the term used in variable and struct names, and comments.

Alexander Korotkov
Better fix for permissions tests in excluded subqueries.

This reverts the code changes in 50c137487c96e629e0e5372bb3d1b5f1a2f71a88,
which turned out to induce crashes and not completely fix the problem
anyway.  That commit only considered single subqueries that were excluded
by constraint-exclusion logic, but actually the problem also exists for
subqueries that are appendrel members (ie part of a UNION ALL list).  In
such cases we can't add a dummy subpath to the appendrel's AppendPath list
without defeating the logic that recognizes when an appendrel is completely
excluded.  Instead, fix the problem by having setrefs.c scan the rangetable
an extra time looking for subqueries that didn't get into the plan tree.
(This approach depends on the 9.2 change that made set_subquery_pathlist
generate dummy paths for excluded single subqueries, so that the exclusion
behavior is the same for single subqueries and appendrel members.)

Note: it turns out that the appendrel form of the missed-permissions-checks
bug exists as far back as 8.4.  However, since the practical effect of that
bug seems pretty minimal, consensus is to not attempt to fix it in the back
branches, at least not yet.  Possibly we could back-port this patch once
it's gotten a reasonable amount of testing in HEAD.  For the moment I'm
just going to revert the previous patch in 9.2.
Update collate.linux.utf8.out for ruleutils.c line-wrapping changes.

Missed in commit 62e666400dddf605b9b6d9a7ac2918711b5c5629.