Try to deal with one of the big problems here, namely, that we

Try to deal with one of the big problems here, namely, that we
can't just output Standard as <p>, or anything else, because we
have structures like:
  this is text <branch>and more text</branch> and more
which would then come out as:
  <p>this is text <p>and more text</p> and more</p>
So we use the OutputParam html_in_par to try to signal when we
are already in a paragraph. It is expected that we will need to
do some bug fixing here.

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@31753 a592a061-630c-0410-9148-cb99ea01b6c8