updated identify anonymous template to operate on all target elements names (whether or not they have id and idref attributes), but then only assign an autogenerated id if it has neither an id or idref.

the identify anonymous template now works on the top level items types (observable, ttp, indicator, etc).

added comments about the purpose of the stylesheet and the templates

this supports issue #28
Merge remote-tracking branch 'origin/beta4_stix11' into beta4_stix11