mq: extend support for the --mq argument to extension commands
This allows commands like `purge' to accept the --mq option.
repository: drop unused rjoin() method
This method was introduced by
cfeeac24fc1e but grepping the history does not
reveal any call. Extensions may use it but the method intent is not even clear
to me.
test-dispatch: drop test for missing working directory
hstuart reported problems when the local Python has been configured to do stuff
and crash before reaching the expected error handler.