parseTH for TH3x

[tamasgal]

Now that we can read TH3[FD], we need to extend parseTH to be able to create an FHist.jl 3D histogram. It's probably pretty easy to do and we can even think about a new interface for histograms, maybe as extension?

[Moelf]

what would the extension do? I think right now UnROOT depends on FHist already

[tamasgal]

Ah, you are right. So it's only the extension of parseTH ;)