Is your feature request related to a problem? Please describe.
The VADER code allows user-defined code to be included for specific problems. The old build system would compile all of these problem-specific workers separately, but this behavior has been removed with the new build system, leaving just a 'vanilla' worker without problem-specific routines.

Describe the solution you'd like
A restoration of the functionality of VADER's makefile to that as of commit 5666436 (the latest before the new build system), where all userFunc_{problem}.c files in the prob directory are detected, and a separate vader_{problem} worker is compiled for each.