OpenXML: add an option to strip change tracking markup (insertions/deletions)

[Chase Tingley]

We currently track revision id (rsid) tags, but we keep insertion/deletion markup related to the "Change Tracking" feature. This can clutter up the resulting segments by introducing markup that has limited value in translation. We would produce better segments if we allowed this markup to be stripped, so that: * Text within "inserted" markup was preserved, but the insertion tags were stripped. * Text within "deleted" markup was stripped, along with the tags.

This would also strip change tracking comments.

This behavior should be optional, in case somebody wants to preserve this markup (for example, for source-to-source translation or other processing).

[Chase Tingley]

This was fixed long ago with the introduction of the bPreferenceAutomaticallyAcceptRevisions flag.