[Distutils] Changes to config file handling

[Greg Ward]

Hi all --

I think I've fixed all the problems Marc-André pointed out with config
files last week, specifically:

  * options in config files can now be spelled either "foo-bar" (like on
    the command line, minus the leading "--") or "foo_bar" (like in
    the code)

  * negative alias options are now respected, eg. "quiet=1" is the same
    as "verbose=0"

Plus I fixed a bug nobody had reported:

  * boolean options now work: previously, "force=0" resulted in an
    attribute 'force' being set to the string "0", which of course
    is true.  As an extra bonus, you can now use a variety of sensible
    representations of true and false: yes, y, t, true, 1, on for true,
    and no, n, f, false, 0, off for false.

And added a feature that was supposed to be in there from the beginning, 
but I just plain forgot about:

  * a "[global]" section where you can set global options; currently,
    only 'verbose' and 'dry-run' are supported here (and of course
    'quiet', since it's the opposite of 'verbose')

As soon as I've checked everything in, I'll put out a new code
snapshot.  Please give it a try and let me know if config files now work 
as you'd expect them to work.

        Greg
-- 
Greg Ward                                      gward@python.net
http://starship.python.net/~gward/