Fix multiline legends for R2014a and R2014b
Fix multiline legends for R2014a and R2014b

It seems to be not possible to determine if a legend entry is messed up in R2014a. As such it is recommanded to use the `sprintf` approach to add a new line in the legend. This works in both R2014a and R2014b.

egeerardyn/matlab2tikz,matlab2tikz/matlab2tikz,LJeub/matlab2tikz,miscco/matlab2tikz,egeerardyn/matlab2tikz,matlab2tikz/matlab2tikz,okomarov/matlab2tikz,PeterPablo/matlab2tikz,nidrosianDeath/matlab2tikz,okomarov/matlab2tikz,RPeschke/matlab2tikz