hgmerge: logic changes Details: - keep automatic merge conflicts in $LOCAL - do not assume that $EDITOR returns proper error code - fix a slight mistake in diff+patch merge success detection (it could succeed if the $EDITOR failed to run)

adding foo
adding bomb
adding a.c
adding dir/a.o
adding dir/b.o
! a.c
! dir/a.o
! dir/b.o
? .hgignore
a.c: unsupported file type (type is fifo)
! a.c