Integrate RNAplot into fornac

[j-4]

Currently we have two code-bases, fornac and RNAplot.

While RNAplot is a static 2D presentation of a single RNA molecule which can be called with D3 on a svg element, fornac builds its own svg element and includes features such as force-field animation, zooming, selecting, edditing or styling with color schemes.

It would be advantageous if we could use RNAplot as the basis of fornac, and add the additional features in for the fornac.
I would include all features which are also important for the static representation (e.g., the color schemes) in RNAplot and import it in fornac where the rest is added.