Fix test suite

Remove useless exception interface

Adding LoggerTrait

Adding AbstractLogger implementation, moving NullLogger to subclass

adds LoggerAwareTrait

Move test class to a test namespace

Change placeholder delimiters

Duplicate info instead of using inheritDoc

Add LoggerAwareInterface and require virtual package

Update package name

Move constants out to a Level class

Add test suite, exceptions, license

Update package name

Add autoload & license

Add interface and null logger

Initial commit