FileConfiguration first cut to push

The push request contains my code for the FileConfiguration, the interfaces for Configuration and the testing code set as well as the test classes built to test the configuration code.
Agreed!
@gdalelio : Calling an _init_ method (and your `reload()` is a form of _init_ method) as the last part of a constructor is a good idea to establish the class' base or initial state. Since you have two constructors and the one is calling the other you'd have to add the `reload()` call in that second constructor only.
Like this:
```java
   ...
   public FileConfiguration(File config) {
      this.propertiesFile = config;
      reload();
   }
   ...
```