tests/test-resolve.out

mq: extend support for the --mq argument to extension commands

This allows commands like `purge' to accept the --mq option.

adding file
% create a second head
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
created new head
% failing merge
0 files updated, 0 files merged, 0 files removed, 1 files unresolved
use 'hg resolve' to retry unresolved file merges or 'hg update -C' to abandon
% resolve -l, should be empty
% resolve -l, should be empty