switch init command to tree command

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_tree_init.c

src/lib66/exec/ssexec_tree_wrapper.c