D360: log: add a "graphwidth" template variable

[yuja (Yuya Nishihara)]

yuja added a comment.


  > I had avoided this change because it might break extensions with their own edgefns. Do you think that's a concern?
  
  It's probably okay to change the function interface. I don't think the current `edgefn`
  is any useful for extensions. And I heard no problem after https://phab.mercurial-scm.org/rHG97cb1aeaca7849bc72d66a8adc6081106f1c9bcf.

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D360

To: hooper, #hg-reviewers
Cc: yuja, mercurial-devel