merge 66 scanctl and 66 scandir in one tool

src/66/66-shutdownd.c

src/66/66.c

src/include/66/ssexec.h

src/lib66/exec/deps-lib/deps

src/lib66/exec/ssexec_boot.c

src/lib66/exec/ssexec_help.c

src/lib66/exec/ssexec_scandir_create.c

src/lib66/exec/ssexec_scandir_remove.c

src/lib66/exec/ssexec_scandir_signal.c

src/lib66/exec/ssexec_scandir_wrapper.c