Speed up experimental worker

- Removed inline sleep call, which slowed down passes n*0.1 seconds, where n is the number of files being tailed
- Inline methods that update data structures which should speed up larger installations
- Make self.active() an attribute lookup instead of a method call
Log to debug instead of warning for file reloading on Darwin architectures
Properly handle rotated files on Darwin architectures
Hack to prevent stupid TypeError: 'NoneType' when running tests via setup.py