The build system now passes compiler directives based on the mode being build. By default data is stored in the source root (and this is encoded into the compiled binary). However, if building in user mode then data is assumed to be at the meson install prefix data directory
Aaron Dotter implimented a C++ version of Frank Timmes' fortran code helmholtz.f90. I have taken that and refactored it to work in the 4DSEE code style. This has mostly involved some light moving of stuff around. The biggest change is removing all globals, and reorienting memory to be heap allocated and contiguous. This is because there was too much memory being stack allocated.
