master.py: added help command

master.py

@@ -16,6 +16,7 @@ from PIL import Image
 
 help_msg = """
 This is the Planète Casio master shell. Type 'exit' or C-D to leave.
+Type 'help' to print this message.
 
 Listing commands:
   members                    Show registered community members
@@ -302,6 +303,7 @@ def enable_user(member):
 
 commands = {
     "exit":                     lambda: sys.exit(0),
+    "help":                     lambda: print(help_msg),
     "members":                  members,
     "groups":                   groups,
     "forums":                   forums,