Add simple Unix socket example by Piet van Oostrum.

Demo/sockets/unixserver.py

@@ -0,0 +1,14 @@
+# Echo server program using Unix sockets (handles one connection only)
+from socket import *
+FILE = 'blabla'             
+s = socket(AF_UNIX, SOCK_STREAM)
+s.bind(FILE)
+print 'Sock name is: ['+s.getsockname()+']'
+s.listen(1)
+conn, addr = s.accept()
+print 'Connected by', addr
+while 1:
+    data = conn.recv(1024)
+    if not data: break
+    conn.send(data)
+conn.close()