Read config.xml files from each directory and combine them into one Configuration object. The data is namespaced with the name of the module.
If no config.xml file is present in a module, assume that it was intentionally left out. An empty Config object is returned.
By default the created configuration for a module will not be namespaced with the module alias. Only when all configuration is requested through the module manager, will the seperate configuration be namespaced.
Added a alias parameter to the 'config' method in the module manager. If an alias is provided, the configuration of that specific module will be retrieved. If no, the configuration of all modules will be combined and returned.
If no plugin.xml file is present in a module, assume that it was intentionally left out. An empty plugin collection will be returned.
If no routes.xml file is present in a module, assume that it was intentionally left out. An empty route collection will be returned.
Trivial: cleaned and ammended the comments inside the abstract module.