Release: bump VERSION_DEVEL.
PO: update template.
Release: update news.
Release: bump VERSION.
issue 3904: disallow old stable and old dev doc in robots.txt
Issue 3905: Doc: Clarify grace note sync workaround

As pointed out in the thread
http://lists.gnu.org/archive/html/lilypond-user/2014-04/msg00540.html
it is necessary to use \grace for the old grace note sync issue.
This commit makes that explicit in the known issues section in the NR
Issue 3911: Two minor fixes in pondings

Fix typo in ponding
Indentation fix in ponding