identify: have consistent output for local repositories
Also, add some extensive testing for it (hardly any in the suite so far).
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
% resolve -l, should be empty