Clarify the meaning of the second argument in --help output

- Create a new pyrasite.tests.utils module
- Popen(shell=True) was causing our test suite not to run on ubuntu
- Use a pidfile to know when a program is running, and rm to stop it

This makes it easier to share code within our test modules, while being able to
write imports that work on py2.4 through 3.

Conflicts:
	pkgs/fedora/pyrasite.spec
	pyrasite/__init__.py
	setup.py