Increase version number
Fix endless recursion

review944002
(transplanted from 59a966b37c3ebeb05a5a63a5c19f5b2e3598f55f)

--HG--
extra : transplant_source : Y%A9f%B3%7C%3E%BE%B0ZZc%A5%C1%9F%5B.5%98%F5_
Prepare release 2.8.1
Added tag 2.8.1 for changeset 5b1a36738ac6
Increase version number
Increase version number
null merge from 2.8
null merge from 3.0
Improve setup.py to allow dev publication

issue3436
issue1891
review2441002