Refactored AEConfig (#2633)

Added a singleton getter instead the public field.
Reduced all fields to private.
Replaced field access with getters.
Added setters where necessary (Dimension/Biome Registration)
Added config options to disable more features.
Splitted Enum name from the config key.
Changed FacadeConfig and Networkhandler similar to AEConfig.init().

src/main/java/appeng/bootstrap/FeatureFactory.java

@@ -59,7 +59,7 @@ public class FeatureFactory
 
 	public FeatureFactory()
 	{
-		this.defaultFeatures = new AEFeature[] { AEFeature.Core };
+		this.defaultFeatures = new AEFeature[] { AEFeature.CORE };
 		this.bootstrapComponents = new ArrayList<>();
 
 		if( Platform.isClient() )