to put more widely useful info before less widely useful info.

overlooked in 7.3 updates.  Not a critical fix but avoids a notice when
the resulting SQL script is executed.

to shared memory as soon as possible, ie, right after read_backend_variables.
The effective difference from the original code is that this happens
before instead of after read_nondefault_variables(), which loads GUC
information and is apparently capable of expanding the backend's memory
allocation more than you'd think it should.  This should fix the
failure-to-attach-to-shared-memory reports we've been seeing on Windows.
Also clean up a few bits of unnecessarily grotty EXEC_BACKEND code.

sockets, rather than failing as it formerly did.  Revert the
thereby-obsoleted patch to make psql supply the localhost default.

Per John Smith.

> * Improve the background writer
>
>   Allow the background writer to more efficiently write dirty buffers
>   from the end of the LRU cache and use a clock sweep algorithm to
>   write other dirty buffers to reduced checkpoint I/O

Per gripe from Josh Berkus.

where it doesn't belong, and put it in the psql reference page.

that is, files are sought in the same directory as the referencing file.
Also allow absolute paths in @file constructs.  Improve documentation
to actually say what is allowed in an included file.

<signal.h>.  Per Andrew Dunstan.

Update FAQ with new URL's for site.

executable file isn't itself a symlink.  We still need to run the
algorithm so that any directory symlinks in the path to the
executable are replaced by a true path.  Noticed this on seeing
pg_config give me a completely wrong answer for --pkglibdir when
I called it through a symlink to the installation bindir.

by Rod Taylor.  The foo_is_visible() functions are relatively slow and
so it pays to check them after checking the name pattern match.

index predicate uses temporary memory for evaluation.  Per example
from Jean-Gerard Pailloncy.

Fixed parsing of defines to make sure they used more than once.

the remainder of the current clog page during system startup.  While
this was a good idea, it turns out the code fails if nextXid is
exactly at a page boundary, because we won't have created the "current"
clog page yet in that case.  Since the page will be correctly zeroed
when we execute the first transaction on it, the solution is just to
do nothing when exactly at a page boundary.  Per trouble report from
Dave Hartwig.