Added the -X/--no-docstrings flag which takes a filename containing a

Added the -X/--no-docstrings flag which takes a filename containing a
list of files to not extract docstrings from when the -D option is
given.  This isn't optimal, but I didn't want to change the semantics
of -D, and it's bad form to allow optional switch arguments.

Bumping __version__ to 1.4.

TokenEater.__init__(): Initialize __curfile to None.

__waiting(): In order to extract docstrings from the module, both the
    -D flag should be set, and the __curfile should not be named in
    the -X filename (i.e. it isn't in opts.nodocstrings).

set_filename(): Fixed a bug where once the first module docstring is
    extracted, no subsequent module docstrings will be extracted.  The
    bug was that the first extraction set __freshmodule to 0, but that
    flag was never reset back to 1.  set_filename() is always called
    when the next file is being processed, so use it to reset the
    __freshmodule flag.

main(): Add support for -X/--no-docstring.