[offlineimap] README.md updates (#206)

[Nicolas Sebrecht]

I took the changes I'm most sure about: eeb7e89ca60b04.
Thank you.

---
Reply to this email directly or view it on GitHub:
https://github.com/OfflineIMAP/offlineimap/pull/206#issuecomment-109955529
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.alioth.debian.org/pipermail/offlineimap-project/attachments/20150608/213e27fc/attachment.html>