fix/implement multiline legend

Proper implementation of multiline legends
Adaption and renaming of the testcase "one_point" to "multiline_labels"

Tested in R2014a and R2014b

Unfortunately in R2014a the line `legendString = get(child, 'DisplayName');` in `findLegendInformation` has issues with multiline fields. A legend with `{'ab','cd'}` is read out as `acbd`. 
`legendString = reshape(legendString,2,length(legendString)/2)` would properly reorder the characters.
I consider this a bug and outside the scope of this pull request.
@egeerardyn How should we handle this?
We do have a little page on our [wiki](../wiki/MATLAB-&-Octave-Version-Compatibility) for those things. The most important resource I know is on the Dynare wiki (mentioned in our wiki).
However, the only good way to check this is to look in the old MATLAB documentation. Most universities with a site license have access to this via the [MATLAB website](http://www.mathworks.nl/help/doc-archives.html). But the only way I know to check it there is to bisect over the releases and try to search for a function.