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

Updated pressure_cut to use separate mat_trans_pc subroutine and to use the mat_trans option even when elements are not cut

Moved material transition code to a separate subroutine and tweaked it to check again for transitions after chaning the material number

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

Added test to ensure the transum values for material transitions are less than or equal to the number of defined materials