examples: move touchtracer into his own directory, and change to be able to run on android

examples/demo/touchtracer/README.txt

@@ -0,0 +1,12 @@
+Touchtracer
+===========
+
+Touchtracer is a simple example to draw lines under every touches detected
+on your hardware.
+
+Android
+-------
+
+You can copy/paste this directory into /sdcard/kivy/touchtracer in your
+android device.
+

examples/demo/touchtracer/android.txt

@@ -0,0 +1,3 @@
+title=Touchtracer
+author=Kivy team
+orientation=portrait

examples/demo/touchtracer/main.py

@@ -76,5 +76,5 @@ class TouchdebugApp(App):
     def build(self):
         return Touchdebug()
 
-if __name__ == '__main__':
+if __name__ in  ('__main__', '__android__'):
     TouchdebugApp().run()