Modernize debian packaging

* Use the new way to package python applications/library as is described here:
    https://wiki.debian.org/Python/Packaging
    https://wiki.debian.org/Python/LibraryStyleGuide
* Correct some lintian warnings (like the missing of a homepage and the
  homepage being on the description)
* Improve documentation on setup.py
* Add install_requires on build.py so it's mapped right to the package
* Remove some unneeded files
* Add a watch file to point to pypi

Change-Id: I8836c2d3eb4a9d61cfed1f09f5dc63f6bd4d489e