manifest: just duplicate the definition of items as iteritems
The forwarding trick was failing test-check-interfaces on Python
3. Duplicating a line of code is easy enough I'm doing that rather
than try and figure out what's going on in any kind of detail.
Differential Revision: https://phab.mercurial-scm.org/D3924
tests: properly sort imports in test-nointerrupt.t
Somehow this was only detected in Python 3.
Differential Revision: https://phab.mercurial-scm.org/D3923