For instance, if you want to add a new cup model called `Plop`, create two files
cpu_plop.hpp and cpu_plop_cpp which contains classes CpuPlopModel, CpuPlop and
CpuPlopAction implementing respectively the interfaces CpuModel, Cpu and
-CpuAction. You also need to define a initializing function like this:
+CpuAction. You also need to define an initializing function like this:
~~~~
void surf_cpu_model_init_plop()
