make_gifs.R to create steel strain animation
Factor interpolation code into helper file
Factor out code and add ESG animation
Make versions with/without true datapoints
Also enable arbitrary GP timetraces
Fix implementation error

I had ONE line of R code, and I couldn't even get it right. :P
Update pdf and tex
Gif code dump

The code is not pretty.  I became increasingly rushed as the deadline
approached.  But if anyone is curious how to make animations like these,
everything they need *should* be here, once all the necessary libraries
are installed.

Oh, and gppois is no longer maintained (sorry!), so you have to
install_github() it (using devtools).