Reduces visibility of internal fields/methods

Reduces the visibility of all fields to private and create setters/getters
when necessary. Exceptions are fields with GuiSync as these need to be
public.

Reduces the visibility of internal methods to private/protected/default when possible.

src/main/java/appeng/container/slot/SlotPlayerInv.java

@@ -31,6 +31,6 @@ public class SlotPlayerInv extends AppEngSlot
 	{
 		super( par1iInventory, par2, par3, par4 );
 
-		this.isPlayerSide = true;
+		this.setPlayerSide( true );
 	}
 }