suggested by PEP 291.

   Slightly modified version of patch from Jon Nelson (jnelson).

   Uche Ogbuji

the sometimes inappropriate warning about where we're installing data files.

compilation).

Tweaked help text.

(Bug spotted and originally fixed by Rene Liebscher; fix redone by me.)

necessary to support it.

Details:
  - build command additionally calls build_scripts
  - build_scripts builds your scripts in 'build/scripts' and adjusts the
    first line if it begins with "#!" and ends with "python", optionally
    ending with commandline options (like -O, -t ...).  Adjusting means we
    write the current path to the Python interpreter in the first line.
  - install_scripts copies the scripts to the install_scripts dir
  - install_data copies your data_files in install_data. You can
    supply individual directories for your data_files:

    data_files = ['doc/info.txt', # copy this file in install_scripts dir
      ('testdata', ['a.dat', 'b.dat']), # copy these files in
                                        # install_scripts/testdata
      ('/etc', ['packagerc']),    # copy this in /etc. When --root is
                                  # given, copy this in rootdir/etc
    ]

    So you can use the --root option with absolute data paths.

rather than 'data'.

'get_inputs()'.

adds the 'install_data' and 'install_scripts' commands; these two
are trivial thanks to the 'install_misc' base class in cmd.py.
(Minor tweaks and commentary by me; the code is untested so far.)