tests/test-gendoc-el.t

write: add the possibility to pass keyword argument from batchget to vfs

We are going to pass atomictemp keyword argument from merge.baychget to
vfs.__call__. Update all the frames to accept **kwargs and pass it to the next
function.

Differential Revision: https://phab.mercurial-scm.org/D1881

#require docutils gettext

  $ $TESTDIR/check-gendoc el
  checking for parse errors