Introduce a decorator for LaTeX style

[synergiator]

While there is a BeautifulTable.STYLE_MARKDOWN, why not offer a BeautifulTable.STYLE_LATEX as well?

Example from here:

\begin{center}
\begin{tabular}{ c c c }
 cell1 & cell2 & cell3 \\ 
 cell4 & cell5 & cell6 \\  
 cell7 & cell8 & cell9    
\end{tabular}
\end{center}

While not really needed on console, could be a nice option to convert sample data sets to LaTeX code in a convenient way saving a lot of typing.