Return VixDiskLib Load Error to DRB Client

When VixDiskLibServer fails to successfully load any
version of the VixDiskLib, cache the failure reason.
Interrogate for the error once the DRB service is started
so that the failure reason can be passed back to the client
for presentation in the UI. Then shut down the DRB service.
Merge pull request #339 from jerryk55/return_vddk_version_error

Return VixDiskLib Load Error to DRB Client