“Internal Task List” and “Running Change List” can be represented by “Version” and “Milestone” fields of an ITS
documents can be referenced in corresponding issues is a seperate field (hyperlink to document storage (SVN, GoogleDocs, …)
Why should addenda be necessary? Why not collect changes (addenda, errata) into a minor version Test Package (e.g. 9.1, …), which is released regularly?
“Summary of changes” could be all resolved issues with a certain Milestone