Mark cWW toggle with cWW family.
Close 2d container div.
Prefix css rules with pdb-2d-view class.

I use pdb-2d-view to indicate we are looking at the 2d view page for each pdb.
By prefixing all rules with this we avoid conflicts with other pages.
Convert IDs and add basic interactions.

Turns out that | is used in some types of css selectors. See:
http://www.w3.org/TR/CSS2/selector.html#attribute-selectors
This conflicts with using | as a separator in our new style ids. In order to
deal with that I modified the getID and getNT methods for nucleotides and
interactions. These now convert the | to _. In addition I activated the basic
interaction controls.
When hovering over an interaction show nucleotides

This will show the nucleotides when hovering. It uses the color of the
interaction to color the letter to make it clear.
Highlight nucleotides on mouseover.

A nucleotide will be highlighted by having its sequence displayed, and any
interactions leading involving it will be highlighted.