Add simple example script from existing documentation. Regenerate netfilterqueue.c with Cython 0.25.2.

examples/print_and_accept.py

@@ -0,0 +1,15 @@
+#!/usr/bin/env python
+from netfilterqueue import NetfilterQueue
+
+def print_and_accept(pkt):
+    print(pkt)
+    pkt.accept()
+
+nfqueue = NetfilterQueue()
+nfqueue.bind(1, print_and_accept)
+try:
+    nfqueue.run()
+except KeyboardInterrupt:
+    print('')
+
+nfqueue.unbind()