Upgrade python packaging to distribute as a platform wheel. (#5)
* Upgrade python packaging to distribute as a platform wheel.
Move to setuptools and separate setup.cfg configuration file.
MANIFEST.in file is no longer needed.
Make sknobs extension python2/3 compatible using the py3c library.
Link to README.md added as setuptools applies a sandbox to avoid
use of outside files.
* Note some package dependencies for building.
* Avoid attempt to update system POD file.
* Include py3c headers to avoid build depenency. Some distros (e.g., AL2) have
no package for this.
* Add include directory for build.
