Gnucap commands and their interface

Hi Al,

I am still working on the Python wrapper for Gnucap, but I am facing a 
problem in finding the available commands. As you said in 
http://article.gmane.org/gmane.comp.gnu.gnucap.devel/307, you don't know 
which commands were installed before starting Gnucap.

However, they could be found by asking the dispatcher which of them are 
currently installed, once Gnucap is started. Would you mind adding some 
members to the DISPATCHER class which return the mapped commands 
(DISPATCHER::begin() and DISPATCHER::end() for instance)?

Another improvement of the commands could be a descriptor: how about 
adding to each class derived from CMD a member function which tells what 
it does? A possible way would be to return a simple string describing 
the command and its parameters, or, even better, a map, each value of 
which would be the description of a parameter.

Thus, each command would be smartly defined: its implementation 
(CMD_XXX::do_it()) and its interface (CMD_XXX::get_description()). It 
may also be interesting for a future "help" command.

Regards,

Xavier