Fix "morph checkout" and system branch deduction

Checkout now does "git remote update" so the local branch gets the
remote branches. This will spend a bit more time, but it's needed for
"morph edit foo" to work when there's an existing "foo" branch in
origin.

System branches are no longer deduced from the currently checked
out branch name of the current git repository, since that doesn't
work when "morph edit" checks out an existing branch. Instead,
we deduce it from the current working directory name (relative to
the mine directory).

0 files changed, 0 insertions, 0 deletions