Feature #2454: Advertise classad in case of glidein failure
Advertize ClassAd if factory removes held glidein
If a glidein is held in a unrecoverable way, and the factory has to remove it,
the FE should be notified, as it affects its operation.
(recoverable helds are arguably not a FE business)
I thus propose we use the same mechanism we use for glideins failing validation;
i.e. an "error classad"