Added examples for Nit to samples.

Signed-off-by: Lucas Bajolet <r4pass@hotmail.com>

samples/Nit/callback_chimpanze.nit

@@ -0,0 +1,45 @@
+# This file is part of NIT ( http://www.nitlanguage.org ).
+#
+# Copyright 2013 Matthieu Lucas <lucasmatthieu@gmail.com>
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# This sample has been implemented to show you how simple is it to play 
+# with native callbacks (C) through an high level with NIT program.
+
+module callback_chimpanze
+import callback_monkey
+
+class Chimpanze
+	super MonkeyActionCallable
+
+	fun create
+	do
+		var monkey = new Monkey
+		print "Hum, I'm sleeping ..."
+		# Invoking method which will take some time to compute, and 
+		# will be back in wokeUp method with information.
+		# - Callback method defined in MonkeyActionCallable Interface
+		monkey.wokeUpAction(self, "Hey, I'm awake.")
+	end
+
+	# Inherit callback method, defined by MonkeyActionCallable interface
+	# - Back of wokeUpAction method 
+	redef fun wokeUp( sender:Monkey, message:Object )
+	do
+		print message
+	end
+end
+
+var m = new Chimpanze
+m.create