chore: split monolithic header to proper program files, add vec2 ruby class to proxy element position etc., other cleanup

samples/button.rb

@@ -1,4 +1,4 @@
-App.run 720, 480, "Button Test", fps: 240
+App.run 720, 480, "Button Test", fps: 60
 
 main_scene = Scene.new
 
@@ -18,7 +18,7 @@ text = ElementText.new :btn_text, default_font, 0xFFFF00, {name: "Me"}, position
 
 rect = ElementRect.new 100, 25, 0xFF0000, position: {x: 50, y: 50}, z: 0, rotation: 60, scale: { x: 1, y: 1 }, alpha: 0.8, click_mode: :block
 
-image_element = ElementImage.new bg_animation, position: {x: 0, y: 0}, z: -1, click_mode: :ignore, alpha: 1
+image_element = ElementImage.new bg_animation, position: {x: 0, y: 0}, z: -1, click_mode: :block, alpha: 1
 
 pp text, rect, image_element
 
@@ -26,7 +26,7 @@ end_scene = Scene.new
 end_scene << rect
 
 text.click do
-  App.switch_to end_scene
+  #App.switch_to end_scene
 end
 
 image_element.click do
@@ -75,6 +75,7 @@ App.update do |delta_time|
     elsif elem == text
       pp "Down over text element"
     end
+    elem.position.x += 10
   end
 end