Revert "Added all the source code for the enum4 style code. This includes updating the makefile to utilize the polya algorithm, adding the source code for the polya algorithm, changing tree_class to be fully functional, creating a new subroutines in labeling_related for enum4 including enum4 and write_single_labeling, adding a new subroutine to sorting.f90 and updating derivative_structure_generator to use the new code." #26
Reverts msg-byu/enumlib#24