Fix SmartState Analysis failures on non-English VMs.

@chessbyte please review.

Text retrieved from non-English Windows VMs may be encoded in
UTF-16. This text may contain byte sequences that are not valid
in UTF-8. Check the text for valid encoding, and convert to UTF-8
as needed.

https://bugzilla.redhat.com/show_bug.cgi?id=1126476
Issue: #293
Issue: #332
Do we need to handle binary data at all in this rescue block?  It wasn't handled previously, but I'm wondering what happens to binary strings that are forced to UTF-8 and then to UTF-16.