Updating the conservative variables

In the previous five steps all corrections to the conservative variables have been determined. Now in subroutine updatecfd.f, these corrections, which were stored in field v, are added to the conservative variables at the start of the increment (stored in field voldaux). The sum is saved again in voldaux, i.e. this field is updated. Subsequently, the physical variables temperature and velocity are determined and stored in field vold(0..3,*). Furthermore, for gases the pressure is calculated and stored in vold(4,*). The L_2 norm of the conservative variables and their increments is calculated and stored for later use in the convergence check.