Adding licensing for examples

Author: pavanky

examples/helloworld.py

@@ -1,4 +1,14 @@
 #!/usr/bin/python
+
+#######################################################
+# Copyright (c) 2015, ArrayFire
+# All rights reserved.
+#
+# This file is distributed under 3-clause BSD license.
+# The complete license agreement can be obtained at:
+# http://arrayfire.com/licenses/BSD-3-Clause
+########################################################
+
 import arrayfire as af
 
 # Display backend information

examples/monte_carlo_pi.py

@@ -1,4 +1,14 @@
 #!/usr/bin/python
+
+#######################################################
+# Copyright (c) 2015, ArrayFire
+# All rights reserved.
+#
+# This file is distributed under 3-clause BSD license.
+# The complete license agreement can be obtained at:
+# http://arrayfire.com/licenses/BSD-3-Clause
+########################################################
+
 from random import random
 from time import time
 from arrayfire import (array, randu)

examples/plot2d.py

@@ -1,5 +1,14 @@
 #!/usr/bin/python
 
+#######################################################
+# Copyright (c) 2015, ArrayFire
+# All rights reserved.
+#
+# This file is distributed under 3-clause BSD license.
+# The complete license agreement can be obtained at:
+# http://arrayfire.com/licenses/BSD-3-Clause
+########################################################
+
 import arrayfire as af
 import math