Logger methods can now be registered by the user.
Users cannot overwrite the stop method now.
Better errors when a logger method already exists.
Improved tests and added static method that returns a list of loggers.
Updated readme with information on getMethods.
Slightly simpler logic, pointed out in code review.
Added safety for instantiation without new.

Also renamed a method and added tests.
Better check for new.

This version will work for classes that inherit from Panopticon too.
v0.2.0
Merge branch 'release/v0.2.0'