Add button to toggle all interactions

The all toggle button will toggle all interactions. It both shows the
interactions and alters the buttons as needed.
Display number as well as sequence on hover

When we hover over a letter in the circular diagram we should also show the
number to allow for easy finding of particular nt. This makes such a
modification. It is a basic version and does have problems when hovering over
an interaction with two nearby nts the labels will overlap. In addition, this
modification should be added to the airport diagram as well, but is not yet.
Check for url parameter before setting view

We would like to link directly to all circular diagrams. The current resonable
default when seeing 2d's is to show an airport if possible. In order to provide
such links we add a check to examine the url parameter for a view=ciruclar
entry. If this happens we never set the view to airport.
Increase size of circle

This increases the size of the circle so that it takes up most of the drawing
region, but still leaves room for the on hover numbers to appear. This makes it
more readable and easier to interact with. I may want to increase the size of
the backbone later.
Make plotting div not empty

This means that when the page loads we do not have the jmol window on the left
side until the diagram is loaded. This is a hack and should be replaced later
by having an animation while drawing which is removed when drawing completes.
Update rna2d.js lib
Remove mode toggle

Mode toggle is not needed with the new library. Thus we remove it from view.
Update code for new rna2d.js lib

The new lib takes a different data format to support having chains. This
requires changes in get_ordered_nts. In addition, the javascript interface is a
little different which is also updated here.
Update code to display no NT errors

If we don't have any nucleotides it shows up by having an empty .nts property
in the first chain entry. The code to display the error message has been
updated to deal with this.
Update check for showing airport

Like the check for no nts the check to see if we have 2d coordinates needed to
be updated. This does that so we show the airport as needed.