Importing setup.py from pypi.

Downlaoding setup.py from the released version 1.5 available on pypi.
Adding metadata about the authors, license, emails, etc. at package level.
Using setuptools, if available.
XXX. A warning is going to be issued if distutils is used, since
`install_requires` is setuptools-only.
Merge pull request #1 from enthought/feature/setuptools

Importing setup.py from pypi.
Merge pull request #12 from enthought/master

Importing setup.py from pypi.