[1073201] revisions due to test failures
- Go back to providing a full avail report if there are inventory sync
  changes.  This isn't really that inefficient agent-side because it's not
  a full scan, but rather a full report.  We still only check avail for
  those resources that have not yet provided avail, and the regularly
  scheduled checks.
- Don't just skip a service scan if one is in progress. We should scan again
  from the top to guarantee nothing gets missed.  So, instead, cancel the
  current scan and add interrupt logic such that it reports what it has
  discovered to that point. And then start a new scan.
- update Discoverytest to explcitly wait for discovery to complete, the
  changes seem to have changed the dynamics of the test.

These changes still need to be monitored to ensure things are behaving...