R1:a57cbbea8c09

Fix for email parsing from Outlook clients.

Summary: D1239 got it mostly right, but some versions of Outlook apparently put a '> ' in front of the 'Original Message' marker, which the parser couln't grok.

Test Plan: Added a test case to the unit tests, applied the patch to my install and asked one of my heathen Outlook using colleagues to reply to a Conpherence post.

Reviewers: epriestley, #blessed_reviewers

Reviewed By: epriestley, #blessed_reviewers

Subscribers: epriestley, Korvin

Differential…