New powny kernel/userspace

PS: Tests failed because the new version of requests/vcrpy contains a bug: https://github.com/kevin1024/vcrpy/issues/94
You could use `pkginfo.get_metadata('powny')` to obtain such metadata.
App code should not "know" about maintainer email, site url etc., so if someone forks this project, he/she could only change `setup.py` and not the actual code. If you do care about copyright, then there is a good practice to add them to each source file header.