Added some demo icons

2d/area_input/engine.cfg

@@ -2,3 +2,4 @@
 
 name="Area 2D Input Events"
 main_scene="res://input.scn"
+icon="res://icon.png"

2d/dynamic_collision_shapes/engine.cfg

@@ -2,3 +2,4 @@
 
 name="Run-Time CollisionShape"
 main_scene="res://dynamic_colobjs.scn"
+icon="res://icon.png"

2d/hdr/engine.cfg

@@ -2,6 +2,7 @@
 
 name="HDR for 2D"
 main_scene="res://beach_cave.scn"
+icon="res://icon.png"
 
 [display]
 

2d/isometric_light/engine.cfg

@@ -2,6 +2,7 @@
 
 name="Isometric 2D + Lighting"
 main_scene="res://map.scn"
+icon="res://icon.png"
 
 [input]
 

2d/light_mask/engine.cfg

@@ -2,6 +2,7 @@
 
 name="Using Lights As Mask"
 main_scene="res://lightmask.scn"
+icon="res://icon.png"
 
 [rasterizer]
 

2d/lights_shadows/engine.cfg

@@ -2,6 +2,7 @@
 
 name="2D Lighting"
 main_scene="res://light_shadows.scn"
+icon="res://icon.png"
 
 [display]
 

2d/navpoly/engine.cfg

@@ -2,6 +2,7 @@
 
 name="Navigation Polygon (2D)"
 main_scene="res://navigation.scn"
+icon="res://icon.png"
 
 [display]
 

2d/normalmaps/engine.cfg

@@ -2,6 +2,7 @@
 
 name="2D Normal Mapping"
 main_scene="res://normalmap.scn"
+icon="res://icon.png"
 
 [display]
 

2d/screen_space_shaders/engine.cfg

@@ -2,6 +2,7 @@
 
 name="Screen-Space Shaders"
 main_scene="res://screen_shaders.scn"
+icon="res://icon.png"
 
 [display]
 

2d/sdf_font/engine.cfg

@@ -2,3 +2,4 @@
 
 name="Signed Distance Field Font"
 main_scene="res://sdf.scn"
+icon="res://icon.png"

2d/splash/engine.cfg

@@ -2,6 +2,7 @@
 
 name="Splash Screen"
 main_scene="res://splash.xml"
+icon="res://icon.png"
 
 [display]
 

2d/sprite_shaders/engine.cfg

@@ -2,3 +2,4 @@
 
 name="2D Shaders for Sprites"
 main_scene="res://sprite_shaders.scn"
+icon="res://icon.png"

3d/sat_test/engine.cfg

@@ -2,3 +2,4 @@
 
 name="SAT Collision Test"
 main_scene="res://sat_test.xml"
+icon="res://icon.png"

gui/rich_text_bbcode/engine.cfg

@@ -2,3 +2,4 @@
 
 name="Rich Text Label (BBCode)"
 main_scene="res://rich_text_bbcode.scn"
+icon="res://icon.png"

misc/instancing/engine.cfg

@@ -2,6 +2,7 @@
 
 name="Scene Instancing Demo"
 main_scene="res://container.scn"
+icon="res://icon.png"
 
 [physics_2d]