Allow an interactive to reference a model with different ids
Update semantic layout config to calculate font-size correctly

As there is no more 1% padding around the whole container.
Zoom into polymerase more during DNA intro

[#47730701]

So there are no DNA strands visible.
Implement next part of the translation intro

[#47731663] [#47732109]
Render correctly initial state of the translation

[#47732109]
Merge pull request #27 from concord-consortium/wip_interactive_manymodels

Allow an interactive to reference a model with different ids
Implement workaround for DNA backbone rendering in Safari

[#48453261]
Ensure that model SVG is clipped correctly

[#48453227]

Explicit setting of "width" and "height" styles solves issues
in Safari.
Implement ribosome animation

[#47732253]
Render ribosome when translation is ready to be started

[#47732253]
Make DNA codons larger so they are better visible in "medium" size
Update interactives related to DNA (fontScale, rm unnecessary button)
Move symbols to the top container; update images

Use SVG images from Upstatement.

[#44616163]
Update ke image; make transparent, solid on hover

Original KE image from Upstatement had colors reversed, and had
no background which made reading text hard.

Both icons are now generally transparent, and become opaque on
mouse hover.

It would be good to also have a hover tooltip. We don't have a
good pattern for this right now (no native solution in SVG, unlike
alt-text in html), but could easily make one.

[#44616163]
interactive diffusion across a membrane updates

[#47225527]
interactive states of matter parameter tweaks

[#45966525]
interactive oil and water bug fix for text box position

[#47832085]
Import textbox callout from mml; update metamodel, tests

If MML textbox has callOut=true and a callout location, a new
property, "calloutPoint," is added to the JSON textbox.

Update one-textbox test to include a callout point.

[#47185435]
Update Classic MW textbox example to include a "hosted" callout

This conversion-example test now includes a textbox with a
callout that is attached to an atom, as well as a text box
with a callout not attached.

[#47185435]
Add callouts to textBoxes in renderer

Callouts are a triangular extension to textBoxes that update each
step to account for motion of the textBox or of a hosted object.

[#47185435]