Added examples for Nit to samples.

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

samples/Nit/fibonacci.nit

@@ -0,0 +1,43 @@
+# This file is part of NIT ( http://www.nitlanguage.org ).
+#
+# Copyright 2004-2008 Jean Privat <jean@pryen.org>
+#
+# 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.
+
+# A simple exemple of refinement where a method is added to the integer class.
+module fibonacci
+
+redef class Int
+	# Calculate the self-th element of the fibonacci sequence.
+	fun fibonacci: Int
+	do
+		if self < 2 then
+			return 1
+		else
+			return (self-2).fibonacci + (self-1).fibonacci
+		end
+	end 
+end
+
+# Print usage and exit.
+fun usage
+do
+	print "Usage: fibonnaci <integer>" 
+	exit 0 
+end
+
+# Main part
+if args.length != 1 then
+	usage
+end
+print args.first.to_i.fibonacci