Added option for viscosity/strain rate strengthening/hardening, added option for sstemp calculation on restart

Fixed bug where boolean variables might not be set to their default values when not given in the input file, added option for fixed cloud

DOES NOT COMPILE!!! This is the first attempt at a complete compaction implementation. Needs debugging/testing!

Added option for a pre-run isostatic compensation stage with a limit on the rate of compensation based on the geometry and a defined max velocity

Cleaned up/improved spinup steady-state thermal calculation option; Added option to fix all surfaces in spinup phase; Added option to fix cloud during spinup phase; Added option for spinup convergence tolerance; Added identification of first time step/iteration/nonlinear iteration; Added option for using spinup phase material numbers

Added option of using previous steps strain rate to soften materials, updated only at the end of the previous step

Added option of defining a dominant material type that will define the element material properties if any volume is present within an element

Replaced ztrans functionality for material transitions below a given depth to a more general transition behavior which allows transitions in at any constant x, y or z value

Added output of yield_ratio and did minor cleanup; moved ziso stuff into bc_definition derived data type