Changed output format for sigma to better cover the range of values. Also removed comma that gives warnings when compiling

Changed expnb to exptag for filenames to allow variable lengths and experiment numbers starting with 0

Added the possibility to request wind stress and ocean drag coefficient (Twater = Cw*u_ice) as outputs.

Incremented iout by one to be able to request number of fgmres iterations by itself; removed fgmres convergence criterion change after 200 iterations

makefile : Put mod first to prevent crash on first compilation ; ice.f90 : rename Numerics to numerics

ice.f90 ; read_pars.f90 : Reading Pars.dat is now performed by the read_pars function instead of within ice.f90.

Added safeguards against too much output for Picard solver regarding residual norm and computing time (iprint)