graphlog: split the actual DAG grapher out into a separate method
This allows extensions like pbranch to use asciigraph() to graph dependencies
for patch branches, but could be used for basically any DAG.
# initial file contents
adding f
line 1
line 2
line 3
# branch 1: editing line 1
# branch 2: editing line 3
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
created new head
# merge using internal:fail tool
0 files updated, 0 files merged, 0 files removed, 1 files unresolved
use 'hg resolve' to retry unresolved file merges
line 1
line 2
third line
M f
# merge using internal:local tool
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
0 files updated, 1 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
line 1
line 2
third line
M f
# merge using internal:other tool
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
0 files updated, 1 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
first line
line 2
line 3
M f
# merge using default tool
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
merging f
0 files updated, 1 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
first line
line 2
third line
M f