Remove disk image dependencies from test file by creating local storage images
from a single disk image.
Clean up some tests to use more JUnit Assert class calls.
Update GUID calculation on Discoverer (management server) and AgentShell.
Allow the GUID to be derived from another agent.properties field.  This
field is named using 'generate_from_' <key name>.  This allows the GUID
to be added to a host in advance rather than through SSH communications to
the hypervisor as is done with KVM.
Add an updated agent.properties file to demonstrate this approach.
Clean up agent.properties by removing unused code.
Add a unit test to compare GUID calculation on AgentShell and Discoverer that
is successful if they match.  Is run only if agent.properties checked in is used.