Add dib-utils

This project was split off diskimage-builder to contain files used
by other projects too.  In order to add it as a dependency of those
projects, it needs to be here.

Conflicts:
	global-requirements.txt

Change-Id: I4fc46f963c6e9819efe2a77b0610f59fd1174773
(cherry picked from commit 97316fa308e2cd89f1b4506086b7a1f90a84cf13)