Get version number from module attribute

Use __version__ atribute from __init__.py to specify the module version
number.

From Python code it is possible to get version using an import statement.

		from reconfigure import __version__

From other scripts, like Makefile, this can be done using a python one line
command:

		python -c "from reconfigure import __version__; print __version__"

See http://www.python.org/dev/peps/pep-0396/ for rationale.
Merge pull request #5 from migonzalvar/load-version-from-source

Get version number from module attribute