init-common: Exporting custom environment variables
init-common: Exporting custom environment variables

Common-init reads config file and exports custom environment
variables from config file and applies them to the running sandbox.

Signed-off-by: Daniel P. Berrange <bb938cf255e055ff3507f2627d214e8e62118fcf@redhat.com>

agx/libvirt-sandbox-debian,agx/libvirt-sandbox-debian,agx/libvirt-sandbox-debian,libvirt/libvirt-sandbox,libvirt/libvirt-sandbox,agx/libvirt-sandbox-debian,libvirt/libvirt-sandbox,agx/libvirt-sandbox-debian