[FEATURE] Shortcut method to select top priority ConfigurationProvider

Before, there was only a method to select all ConfigurationProviders as an array. Now, there is a method to return only the topmost prioritised Provider. If multiple Providers have the same priority, the last one registered will be returned.
Merge pull request #54 from NamelessCoder/claus/getprimaryprovider

[FEATURE] Shortcut method to select top priority ConfigurationProvider