progress: use %d to format ints instead of %s
Due to behavioral changes between '% Ns' and '% Nd' this has some
unfortunate extra dancing. I'm not sure of a better way to solve this
problem.
Differential Revision: https://phab.mercurial-scm.org/D2226
To run the tests, do:
cd tests/
python run-tests.py
See https://mercurial-scm.org/wiki/WritingTests for
more information on writing tests.