Add --version support.
Add --options to allow selection of data displayed.
Bump version to 0.1.0b2.

I'm fairly happy with it now.  I can't publish it for real, though, until
ascii_graph makes its way onto PyPI.
Add pypandoc to requirements.txt.

So I can convert the README to rst when publishing to PyPI.
Update README.
Bring us out of beta: 0.1.0.

I published ascii_graph on behalf of the owner because I was tired of waiting.
-_-