List only the local heads by default and require the remote refs to be
passed as arguments. For example:
git track origin
To make this easier, add support of an `--all` flag to list all remote
refs.
Some distributions ship older versions of `column` that do not have the
flags `-dNLO`. This is a workaround around this limitation that creates
the same output using other tools.
Move `git-track` into its own autoloadable function.
This way it is
better maintainable as in one-liner format and brings the possibility of
having more complexity (e.g. for better portability).
By that it is also now executable as `git-track` as well as `git track`
as before.
