Allow checking out any ref in gitutils
Allow checking out any ref in gitutils

Also changes so that shallow fetch is performed
even when a specific ref is specified.

Signed-off-by: Tonis Tiigi <c2470c48b2d3312d61f94f18d3a1cd113d1915ad@gmail.com>
cpuguy83/cli,riyazdf/cli,Zebrilee/cli,e11137/cli,redpanda/cli,dnephin/cli,thaJeztah/cli,docker/cli,docker/cli,cpuguy83/cli,redpanda/cli,ashfall/cli,Zebrilee/cli,allencloud/cli,thaJeztah/cli,ashfall/cli,dnephin/cli,allencloud/cli,riyazdf/cli,e11137/cli