Cactus: regenerate configure
Cactus: remove support for F77 flags from linux architecture
they are hard-coded to be the F90 flags in configure
Cactus: remove option to use CC as linker
Cactus requires a C++ compiler to build since its main() is in C++ code
Cactus: do not identify gfortran by its name but its version output
copied from the linux known architecture
Cactus: determine Linux C / CXX compiler by their output
using basename does not work for CC=gcc-8 for example
Cactus: remove support for F77 flags from linux architecture
they are hard-coded to be the F90 flags in configure
Cactus: remove option to use CC as linker
Cactus requires a C++ compiler to build since its main() is in C++ code
Cactus: do not identify gfortran by its name but its version output
copied from the linux known architecture
Cactus: determine Linux C / CXX compiler by their output
using basename does not work for CC=gcc-8 for example