Revert "Change core_spec code to work off the stepd_step_rec_t instead of the"

This reverts commit 4294c5617e801514c566d234aaee1a1b5352e0c7.
Revert "Add new is_app flag to proctack_[g|p]_add to distinguish if the pid being"

This reverts commit bf83bcf78a26acc5de4d222e6af8fcf8134bc63d.