Compare Wiki versions and view any asset version before data migration does not work.

View history for a old Wiki asset to see the issue, but also related to any asset type with a history older then the 1.8 data migration.

Here is an example: http://next.dev.curriki.org/xwiki/bin/view/Coll_jmarks/CurrikulumBuilderOverview?bc=&viewer=history

1) If you view an old version (like V1.18 - http://next.dev.curriki.org/xwiki/bin/viewrev/Coll_jmarks/CurrikulumBuilderOverview?rev=1.18 ) it does not display as a asset, as the wiki page only has the #includeForm("XWiki.AssetTemplate").

2) If you compare two older version or between an old version and a new version, then it too does not work because the Wiki text AND the meta data have changed objects.(in the asset above compare an old version to the last version.)

What is needed in the case of a view or compare from the old data model is to dynamically convert to a temp version of the resource, which seems like would involve running the asset convert script on the single asset version much as is done on a roll back, and then viewing or comparing to that.