Limiting supercapacitor charging inrush
Answering my own question.

Using a P-channel FET as a current limiter seems to be a quite common technique. A good introduction can be found in this EETimes article.

The technique has been packaged in multiple $1-$2 ICs, including:
https://www.fairchildsemi.com/datasheets/FP/FPF2123.pdf
http://www.diodes.com/_files/datasheets/AP255x.pdf
http://ww1.microchip.com/downloads/en/DeviceDoc/mic20xx.pdf

This page is an example of someone using the Fairchild chip in a supercap charging application.

Using LTSpice, I compared the "limit the current with a resistor" approach (presented in the first link of the question) with the PNP+FET approach (presented in the EETimes article above). The PNP+FET circuit is roughly 3x faster.