pull: allow to specify multiple sources I end up needing that on a regular basis and it turn out to be very simple to implement. See documentation and test for details. Differential Revision: https://phab.mercurial-scm.org/D10159

pull: pre-indent a part of the function We are about to run it in a loop, so lets pre-indent it to clarify the actual change in the next changesets. Differential Revision: https://phab.mercurial-scm.org/D10158

command: clarify `postincoming` return and that return handling The command should return None or a return code. The previous code was returning boolean directly relying on the fact that `True → 1` and `False → 0`. This is a good road to troubles, so lets be explicit about that return. Differential Revision: https://phab.mercurial-scm.org/D10157

hg: make `clean` return consistent with the `update` function The function return a boolean and is used as such. Lets be explicit about it. Differential Revision: https://phab.mercurial-scm.org/D10156

tests: rename `test-pull` to `test-pull-network.t` If is mostly about ssh and http interaction so lets avoid confusion with a generic `hg pull` test Differential Revision: https://phab.mercurial-scm.org/D10155

tests: move a test about update in test-pull-update.t Differential Revision: https://phab.mercurial-scm.org/D10154