autogenerated IDs (coming from xslt) should not show to the user in output of stix-to-html

When displaying the Malware_Instance_Object_Attributes (Instance Object Attributes) for a Bundle, the auto-generated ID for the Object is displayed in the ID column, even if there is none in the input file. If there is no such ID, we should just display "No ID" or something of the like.
The same issue as the one above applies to AV_Classifications (e.g. in the bundle_av_classifications example), except in this case AV_Classification elements cannot have IDs, so we should just remove this column when displaying them.

FYI, this is split out from issue #61

STIXProject / stix-to-html