make exceptions narrower and thus code easier to inspect for 'IOException's
https://bugzilla.redhat.com/show_bug.cgi?id=916625 Add missing calls to factory.onIOError()
Narrow down exceptions again
Add more calls to ioErrorException handler
Merge pull request #1017 from FranciscoBorges/nfsHang

Small fixes motivated and related to the NFS hang bz