Improve rendering of sub and superscripts in LaTeX

src/latexdocvisitor.cpp

@@ -199,10 +199,10 @@ void LatexDocVisitor::visit(DocStyleChange *s)
       if (s->enable()) m_t << "{\\ttfamily ";   else m_t << "}";
       break;
     case DocStyleChange::Subscript:
-      if (s->enable()) m_t << "$_{\\mbox{";    else m_t << "}}$ ";
+      if (s->enable()) m_t << "\\textsubscript{";    else m_t << "}";
       break;
     case DocStyleChange::Superscript:
-      if (s->enable()) m_t << "$^{\\mbox{";    else m_t << "}}$ ";
+      if (s->enable()) m_t << "\\textsuperscript{";    else m_t << "}";
       break;
     case DocStyleChange::Center:
       if (s->enable()) m_t << "\\begin{center}"; else m_t << "\\end{center} ";

src/latexgen.cpp

@@ -293,6 +293,7 @@ static void writeDefaultHeaderPart1(FTextStream &t)
        "\\usepackage{makeidx}\n"
        "\\usepackage{multicol}\n"
        "\\usepackage{multirow}\n"
+       "\\usepackage{fixltx2e}\n" // for \textsubscript
        "\\PassOptionsToPackage{warn}{textcomp}\n"
        "\\usepackage{textcomp}\n"
        "\\usepackage[nointegrals]{wasysym}\n"