Add optional label to pulldown

[#44809641]

It can be placed on the left side or above pulldown menu ("labelOn"
component property).
Use pulldown label in Dissolve Compare interactive

[#44809641]

Previously there was a text component used for that.
Add optional label to radio buttons group

[#44809641]
Use pulldown and radio labels in interactive presenting these components

[#44809641]
Change default value of "labelOn" of pulldown to "top"

[#44809641]
Update Dissolve Compare interactive

[#44809641]
Support "fontScale" property of a semantic layout container

[#45241949]
Use custom font scales for containers in "Why did the can collapse"

[#45241949]

So banner links are not affected.
Update docs of the callAt and callEvery functions

[#44616277]
Remove lightgl.js submodule

It was unused.
Remove lightgl.js from license info
Remove lightgl.js from Makefile
Add top bar and offset model within interactive

Initial work for starting to make interactive look
like Upstatement's work. Add blue background, white
top-bar, and update layout to pad inner part of interactive 
to leave a little room between borders and model (and all 
other components with top/left of 0).

[#44616109]
Add radial gradient to background and curved corners

[#44616109]
Rm iframe border

Now that we have a clear frame, we should view it the 
way it would be embedded in a webpage. iframe resize 
handle is still visible and functional.
Create bottom bar for frame; move credits to it

Arrange components by reducing "availableHeight" by
size of bottom bar.

[#44616109]
Make about link always visible, show credits if no About

To keep standardized layout, we should always have an
About link, which will show the CC credits dialog if
there is no other About text.

[#44616109]
Add padding to bottom of interactive as well

[#44616109]
Move dependencies require to build project to "dependencies"

.. from "devDependencies".
Remove unnecessary browserify dependency (used before RequireJS)