- replace deprecated "export_url_vars" by "export_vars -url"
- fix bracing in "export_vars -form"
- add default value
- replace deprecated "item::get_url" by "content::item::get_virtual_path"
- add missing nonpositional arg
- use property "doc(title)" throughout oacs-5-8 instead of "title" to get rid of warnings in error.log of the form:
     Warning: /forums/message-view has no doc(title) set.
  Using doc(title) is required in blank-master.tcl but was used so far only in a few packages
- add missing message key
- fix incorrect message key names