pythonresources: elaborated comment on preferences, added new options

files/dirs.  Slight editing.

 suggested by Nils Fischbeck, adapted by Fred

command instead of the non-existant "select set".  (Fred)

to override an internal sioux routine and (b) we have to override the
"about sioux" menuitem after sioux has created its menus.

(which have the descriptions of the errors in comments) and
generates errors.txt, macerrors.py and errors.rsrc

application, not from some system extension that happens to use the
same resource id.

  - Update lastyield correctly
  - Do event handling if PyMac_YieldEnabled > 0 (previous cmd-. fix
    broke this)
- Use our own GUSISpin routine: fixes crash when exiting with sockets
  open and keeps windows, etc reacting consistently when waiting for
  accepts(), etc.

add-change-log-entry-other-window is so bad about guessing the proper
name of Python functions, methods and variables, so finally I wrote
the following (unidiff patch against python-mode.el 2.73):

Per Cederqvist <ceder@signum.se>

Added more specific directions for editing the environment on Windows '95.
Made the section headers more visible.

hurt for XEmacs.