tests/test-gendoc-ru.t

scmutil: extract helper functions that returns human-readable change id

We do "'%d:%s' % (ctx...)" at several places, so let's formalize it. A low-
level function, formatrevnode(ui, rev, node), is extracted so we can pass
a manifest rev/node pair.

Note that hex() for manifest output can be replaced with hexfunc() because
it is printed only when debugflag is set.

i18n/de.po is updated so test-log.t passes with no error.

#require docutils gettext

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