Tagged release candidate #3 for 6.5.5

[Eygene Ryabinkin]

https://github.com/OfflineIMAP/offlineimap/releases/tag/v6.5.5-rc3

I think that it will be very good to have 6.5.5 released to the
world with all fixes (and new bugs), so I created 6.5.5-rc3.
I expect short timeout (around a week) for testing and polishing,
and if all will go fine, the long overdue 6.5.5 should be finally
out.

Please, test and report back.

Branch "master" is currently synchronized with 6.5.5-rc3, so you
can use it for testing or RC3 too.
-- 
rea