Convenience methods for config object
Introduction of a new layer in the configs: :internal
This layer is supposed to be provided within the Gem and have the name of the script (script_name).
 TODO: Improve tests
Layers handling improvements. notion of ordered layers introduced.
Tests improvements
TODO: check regarding manually introduced layers
Manually introduced layers now fully work with low priority
Tests done accordingly
A lot cleaner tests
Mainly test improvements
Minor forgot
Test for the internal config file.
Minor
Minor
Fix for gem config file place