Doc-it: translate @ref links to translated nodes

Doc-it: translate @ref links to translated nodes

Not translated @ref links work fine in HTML output, but create
broken (undefined) links in PDF output.
I found a list of all @ref in a manual, without repetitions,
with the following command:

  cd Documentation/it/MANUAL
  grep -oh -e @ref{.*} * | sort -u > list.txt

Then I found the translation used as @node with:

  git grep -B2 "@translationof ENGLISH LINK"

Finally I translated each instance with sed, e.g.:

  sed -i "s|@ref{Accidentals}|@ref{Alterazioni}|g" *.itely

The replacement is not complete. I must find a smarter way.