reverse direction of the supervisor/advisor tree

[TS404]

Currently the arrows point from students to their advisors, but this is counterintuitive to read (reverse-chronological).

A better option would be to have the arrows follow the follow the flow of time. Example: https://tinyurl.com/y6tzmfzc

That way the vertical viewing option also shows it like a family tree:

[egonw]

I agree the three is hard to navigate. @TS404, what about coloring the people by the century they got their PhD in (additionally)?

[egonw]

See also https://github.com/fnielsen/scholia/issues/1293

[fnielsen]

We should also color the person in question.

[fnielsen]

...and get rid of the GAS query.