lattice.f90, FEsolving.f90: explicitly defined public functions and variables, all others are now private
numerics.f90: changed output format of real numbers, now instead of 0.1eX 1.0e(X-1) is printed to screen
Makefile: now using correct Optimization flags for OPTIMIZATION=AGGRESSIVE
DAMASK_spectral_AL.f90: improved, but still testing. Stress BCs now seem to be handled correctly
explicitly defined all functions in as either public or private in the modules to have a quick overview on all functions and parameters that are available