#291 Latex renderer does not escape underscores

[Matthew Horridge]

I'd like to report a bug for the http://owl.cs.manchester.ac.uk/converter/
conversion to Latex:
it doesn't escape underscores in section names, and latex complains. Eg
\subsubsection*{RC16.Area_of_Interest} should be
\subsubsection*{RC16.Area\_of\_Interest}