simplemerge: let filemerge check for binary inputs This is similar to the previous patch, but here we put a specialized copy of `simplemerge._verifytext()` in the the `filemerge` module instead. Differential Revision: https://phab.mercurial-scm.org/D12147

#require docutils gettext

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