Add flipme attribute to textboxclass

Instead of calculating the y-position of the text box when it's created,
we will store a flag that says whether or not the text box should be
flipped in Flip Mode (and thus stay right-side-up), and when it comes
time to draw the text box, we will check Flip Mode and calculate the
position then.

desktop_version/src/Textbox.cpp

@@ -21,6 +21,8 @@ textboxclass::textboxclass(void)
     tg = 0;
     tb = 0;
     max = 0;
+
+    flipme = false;
 }
 
 void textboxclass::centerx(void)