Fix comments about zlib version and URL.

data struct before calling gethostby{name,addr}_r(); (2) ignore the
3/5/6 args determinations made by the configure script and switch on
platform identifiers instead:

AIX, OSF have 3 args
Sun, SGI have 5 args
Linux has 6 args

On all other platforms, undef HAVE_GETHOSTBYNAME_R altogether.

Chris Lawrence sent me a broken version; this one is a tad simpler and
more conforming to the standard.

This is in response to a comment from Wes Rishel <wes@rishel.com>.

with egcs (after setting EXE=.exe).  Patch by Norman Vine.

ProcessHierarchy's changes to support reading from a remote URL in
ProcessDatabase).

As requested by Bill Janssen.

donated by David Arnold.

- Use HAVE_GETHOSTBYNAME_R_6_ARG instead of testing for Linux and
glibc2.

- If gethostbyname takes 3 args, undefine HAVE_GETHOSTBYNAME_R --
don't know what code should be used.

- New symbol USE_GETHOSTBYNAME_LOCK defined iff the lock should be used.

- Modify the gethostbyaddr() code to also hold on to the lock until
after it is safe to release, overlapping with the Python lock.

(Note: I think that it could in theory be possible that Python code
executed while gethostbyname_lock is held could attempt to reacquire
the lock -- e.g. in a signal handler or destructor.  I will simply say
"don't do that then.")

Here's a patch to fix the race condition, which wasn't fixed by Rob's
patch.  It holds the gethostbyname lock until the results are copied out,
which means that this lock and the Python global lock are held at the same
time.  This shouldn't be a problem as long as the gethostbyname lock is
always acquired when the global lock is not held.

    the end of loop was incorrect, and failed when the flushmode != Z_FINISH.
    Logic cleaned up and commented.

    different flush values Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FULL_FLUSH.

a much less formalistic way.  Just keeping this around for possible
future reference.

a block cannot be freed, add its free items back to the free list.
This is necessary to avoid leaking when Python is reinitialized later.

a block cannot be freed, add its free items back to the free list, and
add its valid ints back to the small_ints array if they are in range.
This is necessary to avoid leaking when Python is reinitialized later.

object that supports the buffer interface (e.g. strings, arrays).

negative size for PyBuffer_FromMemory.  Greg Stein.

typical published manuals, so people can more easily see what they're
really asking for.  ;-)

Revise the verbatim environment: simple implementation, but more
compatible if a document also add \usepackage{verbatim} at the
beginning.

Declare \modindex, \bimodindex, \exmodindex, and \stmodindex
obsolete.  These still work just fine, but \declaremodule should be
used instead.  The obsolete macros will print a warning on standard
out.

If a filename on Windows starts with \\, it is converted to a URL
which starts with ////.  If this URL is passed to urlparse.urlparse
you get a path that starts with // (and an empty netloc).  If you pass
the result back to urlparse.urlunparse, you get a URL that starts with
//, which is parsed differently by urlparse.urlparse.  The fix is to
add the (empty) netloc with accompanying slashes if the path in
urlunparse starts with //.  Do this for all schemes that use a netloc.