Fix: for the thermics: (1) revise the calculation of thermal conductivity when SOC insulating effect is activated, which follows Lawrence&Slater,2008
(2) add the option to read prescribed SOC map only used in thermics for the SOC insulating effect.
for the permafrost carbon dynamics:
(1) corrected a bug related to time step
(2) change the condition for cryoturbation, and the default configuration for cryoturbation method
Done by dan.