Shellify all of devtest.sh.

It is possible now to run a full devtest setup from the script.
We have also now inverted the greed in the image name globbing when
loading images into glance. This is necessary to support building in a
directory with a period in the name (i.e. ~/.cache/).

Change-Id: I75acd6cbc583b7c18a615ad72ee595977441df59