Got rid of compiler warnings (closes feathersui#504)

Author: joshtynjala

source/feathers/controls/text/BitmapFontTextRenderer.as

@@ -1032,6 +1032,11 @@ import starling.text.BitmapChar;
 
 class CharLocation
 {
+	public function CharLocation()
+	{
+
+	}
+
 	public var char:BitmapChar;
 	public var scale:Number;
 	public var x:Number;

source/feathers/layout/LayoutBoundsResult.as

@@ -12,6 +12,14 @@ package feathers.layout
 	 */
 	public class LayoutBoundsResult
 	{
+		/**
+		 * Constructor.
+		 */
+		public function LayoutBoundsResult()
+		{
+
+		}
+
 		/**
 		 * The visible width of the view port. The view port's content may be
 		 * clipped.

source/feathers/layout/ViewPortBounds.as

@@ -13,6 +13,14 @@ package feathers.layout
 	 */
 	public class ViewPortBounds
 	{
+		/**
+		 * Constructor.
+		 */
+		public function ViewPortBounds()
+		{
+
+		}
+
 		/**
 		 * The x position of the view port, in pixels.
 		 */