py3: handle keyword arguments correctly in hgext/patchbomb.py The keys of keyword arguments must be str on Python 3 which is unicode. This patch make sure we pass keyword arguments with keys are str everywhere in this file and access the keys depending on whether they are bytes or str. This patch uses pycompat.{byteskwargs|strkwargs} and somewhere it also added r'' to prevent transformer from adding a b'' over there. Differential Revision: https://phab.mercurial-scm.org/D974