IPTC time without timezone raises exception
Exiv2 will raise an exception "Unsupported time format" when reading an invalid time. This was caused by an IPTC time without mandatory timezone information.
1) not panik but just skip a dataset if it can't read it and
2) be able to read a valid time in HHMMSS format without timezone information to cater for buggy IPTC writing software.