Release 0.1.0

Clean up setup.py and related files to get ready to push the
package to PyPI.

Added AUTHORS.rst and HISTORY.rst to explicitly list contributors
and changes.

Break version out into a separate module and load in setup.py using
the pattern from http://stackoverflow.com/a/16084844/386210.
Also load in clarify/__init__.py to follow package conventions.

Ignore .egg files/dirs and dist directory in .gitignore.

Convert the Markdown README into rst so it will show up all
pretty on the PyPI page.

Add a short description, keywords and classifiers as arguments
to setup().

Add MANIFEST.in file so README, AUTHORS, HISTORY, etc are included
in the distribution.