Cu-cat

passing pyg gpu/cpu tests

no need for dirty_cat dependency, even speeds up cpu parallel operations via mat_mul when system mem allows

no need for dirty_cat dependency, even speeds up cpu parallel operations via mat_mul when system mem allows

no need for dirty_cat dependency, even speeds up cpu parallel operations via mat_mul when system mem allows

more efficient available gpu-memory checking

passthru of datetime works around lack of datetime in cudf in cu-cat, but still needs to be accepted into graphistry cudf and/or feat/gpu-feat branches which lazy force everything into cudf. this is in order for time bar in graphistry plot to work