Fixing bug: object with newer timestamp overwrites object with older timestamp.
Fixing problem with import: placeholder was only identified as such if it was the latest revision of the object. This worked fine for STIX et al, where we always have the import date as timestamp, but would not work for imports with older timestamps. Also, there was a problem that overwriting a placeholder and changing the timestamp during that overwrite might actually lead to conflicts with already existing objects.
Removing constraint in get_or_create_iobject to supply timestamp.
Removing constraint in get_or_create_iobject to supply timestamp.
Logger INFO on object creation had been commented out by mistake.
Exceptions raised during import of one file are caught and logged; if there are other files to be imported, the import is then carried out for those files.