[offlineimap] utime_from_header: restrict to Maildir type (#184)

[Nicolas Sebrecht]

Also refactor the code. The implementation was wrongly put in folder/Base.

---
Reply to this email directly or view it on GitHub:
https://github.com/OfflineIMAP/offlineimap/issues/184
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://alioth-lists.debian.net/pipermail/offlineimap-project/attachments/20150327/389d5e5c/attachment-0002.html>