adding some usage information to provider.{query,update} to show how to use the --selection option; and fixing some argparse help that showed incorrect usage; refs #46
fixing a bug in console.format_dict, where passing it an empty dictionary would cause an error
make the argparse parser generated by cli.Base a little more configurable, so we can override the help and error handling behaviour
moving the module management command into the Mercury console itself, and invoke methods through the existing cli implementation
tweak the repoman.manager.* implementations, so they behave well inside a Mercury shell (not calling sys.exit for a start)
if the user tries to install a module, and doesn't have a repository available, offer to create it inline