LaTeX export: Protect <...> arguments for BEAMER export

LaTeX export: Protect <...> arguments for BEAMER export

Bill Jackson writes:

> When exporting to LaTeX, curly brackets in a command will be escaped
> if that command also contains angle brackets.  This can be a problem
> when using beamer.  An example input file:
>
> ------------------------------------------------------------------------
>
> #+LaTeX_CLASS: beamer
>
> * The One and Only Frame
>  When LaTeX \alert<2>{commands} contain angle brackets, the curly
>  brackets are erroneously escaped in the output.  \alert{Commands}
>  that do not contain angle brackets work properly.
>
> ------------------------------------------------------------------------
>
> Typing C-c C-e l will generate the output file:
>
> ------------------------------------------------------------------------
>
> % Created 2010-01-15 Fri 13:57
> \documentclass{beamer}
> \usepackage[latin1]{inputenc}
> \usepackage[T1]{fontenc}
> \usepackage{graphicx}
> \usepackage{longtable}
> \usepackage{float}
> \usepackage{wrapfig}
> \usepackage{soul}
> \usepackage{amssymb}
> \usepackage{hyperref}
>
>
> \title{escCurly}
> \author{}
> \date{15 January 2010}
>
> \begin{document}
>
> \maketitle
>
> \begin{frame}
> \frametitle{Outline}
> \setcounter{tocdepth}{3}
> \tableofcontents
> \end{frame}
>
> \begin{frame}
> \frametitle{The One and Only Frame}
> \label{sec-1}
>
>  When \LaTeX{} \alert<2>\{commands\} contain angle brackets, the curly
>  brackets are erroneously escaped in the output.  \alert{Commands}
>  that do not contain angle brackets work properly.
> \end{frame}
>
> \end{document}