Enhancements to reuse sliboot controller

Update sliboot implementation so that controller can be imported into
other apps to implement SLI-API API (notably healthcheck)

Change-Id: I1f1e37eb3af583c609c0b074946abdfe58b25a33
Issue-ID: CCSDK-2948
Signed-off-by: Dan Timoney <dtimoney@att.com>
9 files changed