mostly only references glossary entries.

- removed use of the string module
- fixed some broken markup

- update a couple of URLs to point to more recent portions of
  python.org

(Revised from the original patch contributed by Michal Pasternak.)

Also, make a couple minor fixups elsewhere.

Thou shalt not count to two unless proceeding to the number three.

throughout the documentation.

usually preferred.

Brett found that the tutorial didn't really explain what was happening
with exception targets.  Hopefully, this sheds some light on the subject.

  detail
- fix minor markup nit

(Contributed by Gerritt Holl)

* Remove the last mentions of string exceptions
* Reference a third-party repository of programs
* Minor clarification of comp.lang.py posting volumes

Fixed a nit.

as default values of function/method parameters.

Fred

but convenient in interactive sessions.