Source control: prefer remote named "origin"

[bengourley]

This update includes a contribution from @marktran (thanks Mark!) to select the url from the remote named origin when attemping to detect the git repo URL. Previously it would just choose the first remote from the list output by git remote -v, which lists in alphabetical order.

Since the command git remote get-url <name> will error if the provided remote does not exist, I added a fallback to the original logic.