DEL uses 'visible_', TRI uses 'visible'

[mdsumner]

easier atm to fix DEL, but maybe it should be with the underscore

[mdsumner]

confusing bugs, given sharing of TRI class :)

https://github.com/hypertidy/silicate/blob/master/R/plot.R#L157

[mdsumner]

Doing it, use visible because anglr uses it as a function argument, and hopefully no silicate disruption

[mdsumner]

FIXED 8b60ec1