If we indiscriminately register everything in a module with wafterpreter, this can have the unintended consequence of overwriting wafterpreter's own methods and properties (since the code above selects everything and not just module functions).  Consequently, we are only registering the functions that Cmd will be looking for. 

Cmd automatically looks for a help_ method when the user issues "help", and Cmd automatically looks for a complete_ method when the user presses <TAB> after completing the command name.