add busybox's diff and fdisk
updated ToDo
Revert "add busybox's diff and fdisk"

This reverts commit e63cb46954a364d947fa770424495c126d99bd98.
use cfdisk and fdisk from util-linux
added gpart
update cfdisk in ToDo
[gptfdisk] optimized  flag handling
[wipe] added
[gpart] removed unused flags