[PATCH 0 of 1] convert: use branchmap to change default branch in destination (issue3469)

[lstewart at room52.net]

Hi,

I've finally managed to come back to this and I believe I have a workable
solution that is not VCS dependent like my previous attempts. Hoping it
passes muster and we can finally close issue 3469.

Please keep me CCed as I'm not on the list.

Cheers,
Lawrence