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/BlockDefinitionBuilder.java

@@ -184,7 +184,7 @@ class BlockDefinitionBuilder implements IBlockBuilder
 	@Override
 	public <T extends IBlockDefinition> T build()
 	{
-		if( !AEConfig.instance.areFeaturesEnabled( features ) )
+		if( !AEConfig.instance().areFeaturesEnabled( features ) )
 		{
 			return (T) new TileDefinition( registryName, null, null );
 		}