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/client/gui/widgets/GuiScrollbar.java

@@ -53,7 +53,7 @@ public class GuiScrollbar implements IScrollSource
 		}
 	}
 
-	public int getRange()
+	private int getRange()
 	{
 		return this.maxScroll - this.minScroll;
 	}