Implemented an alias system for the modules

This is purely to basically solve the issue with certain modules
having to provide multiple stats, like in the cpu module. There fore
I also started on the cpu module, this has aliases enabled. This means
that you'll end up with the 'modules' "cpu cpu0 cpu1 cpu2 cpu3" in case
you have 4 cpus. Besides that it doesn't really offer anything special yet.

Signed-off-by: Toon Schoenmakers <nighteyes1993@gmail.com>