support for posix semaphores.

- .wsdl --> Web Service Definition Language
- .xpdl --> XML Process Definition Language

Indicate to the user when this is an upgrade installation.
Make CHM file non-advertised.
Backported to 2.4.

Backported to 2.4

Made traceback unconditional, to avoid lock contention problems when logging errors occur in a custom importer (SF path #1158052).

Added optional encoding argument to file handlers. Made traceback import unconditional, to avoid lock contention problems which occur when logging from custom importers (SF patch #1158052)

Bug #1160802:  Can't build Zope on Windows w/ 2.4.1c1.

MSVCCompiler.initialize():  set self.initialized to True, as suggested
by AMK.  Else we keep growing the PATH endlessly, with each new C
extension built, until putenv() complains.

No change to NEWS because the patch that created this bug is also new
for 2.5a1 (so there's no change here to any code yet released from HEAD).

etc., had comments after the colon, and some other cases. This patch
take a simpler approach that doesn't rely on looking for a ':'. Thanks
Simon Percivall!

new builtins.

socket.gethostname() in the check for a valid return.

Also clarified docs (official and docstring) that the value from gethostname()
is returned if gethostbyaddr() doesn't do the job.

- add support for additional markup: \leq, \textbar, \textit
- add a comment about the non-support for the Euro character
(ported from release24-maint branch release 1.10.4.2)

(ported from release24-maint branch revision 1.10.4.1)

(ported from release24-maint branch revision 1.86.2.3)

of multiple fields.  This provides direct support for sorting by
multiple keys.

example