Aligned textbox to bottom of screen.

include/dawn/vn/vntextbox.h

@@ -35,6 +35,9 @@ typedef struct {
   /** X, Y Position of the textbox */
   float x, y;
 
+  /** Readonly values for the dimensions of the textbox */
+  float width, height;
+
   /** Animation of the textbox */
   float textScroll;