rewriteutil: check for divergence
This code is adapted from the code in the evolve extension. It seems
to be equivalent as far as the evolve extension's test suite can tell
(the only impact when making their `precheck()` delegate to our
version is that error messages are less detailed).
I had to change the error message to work with "change branch of"
being inserted as the action.
Differential Revision: https://phab.mercurial-scm.org/D10518
# name space package to host third party extensions
from __future__ import absolute_import
import pkgutil
__path__ = pkgutil.extend_path(__path__, __name__)