spurious title boxes

[kohlhase]

In the XSLT that presents statements, we create a

<div class="omdoc-definition" id="unary-nats-def-by-rules.def">
  <div class="omdoc-titlebox">
     <span class="omdoc-titleword">Definition</span>
  </div>
  ...

There is some code in the style sheets that tries to restrict the titlebox generation (which leads to a Definition: \newline; the newline is annoying if there is nothing behind it) to cases when there is a title or a @for attribute.

This does not seem to work any more.