want no output.  Still no option for a happy medium though.
Added "--help" global option.
Changed 'parse_command_line()' to recognize help options (both for the
  whole distribution and per-command), and to distinguish "regular run"
  and "user asked for help" by returning false in the latter case.
Also in 'parse_command_line()', detect invalid command name on command
  line by catching DistutilsModuleError.
  a 'negative_opt' class attribute right after 'global_options'; changed
  how we call 'fancy_getopt()' accordingly.
Initialize 'maintainer' and 'maintainer_email' attributes to Distribution
  to avoid AttributeError when 'author' and 'author_email' not defined.
Initialize 'help' attribute in Command constructor (to avoid
  AttributeError when user *doesn't* ask for help).
In 'setup()':
  * show usage message before dying when we catch DistutilsArgError
  * only run commands if 'parse_command_line()' returned true (that
    way, we exit immediately when a help option is found)
  * catch KeyboardInterrupt and IOError from running commands
Bulked up usage message to show --help options.
Comment, docstring, and error message tweaks.