combinedroot: use a prebuilt busybox

Busybox for Android
v1.21.1 Stable
built by Linus Yang

[Changelog]
- Oct 8, 2013: Update to 1.21.1 stable
- Oct 15, 2012: Fix `df' command issue with arguments
- Aug 12, 2012: Update to 1.20.2 stable

[Features]
- Tested on Android 2.1, 2.3, 4.0, 4.1 and 4.3.
  Should be capable with all Android devices
  (** Use at your own risk **)
- ELF armv5te binary (statically linked)
- More suitable for Android than the prebuilt
  ARM binaries from busybox.net
- IPv6 support, using own DNS resolver, correct user name display
  and more improvements for Android

[Install]
$ wget http://yangapp.googlecode.com/files/busybox-1.21.1
$ mv busybox-1.21.1 busybox
$ chmod 755 busybox
$ ./busybox --install [INSTALL_DIR]

[Build]
You can build by yourself from my github's project:
(forked from tias/android-busybox-ndk)
https://github.com/linusyang/android-busybox-ndk

[Information]
BusyBox v1.21.1-linusyang (2013-10-08 21:14:44 CST) multi-call binary.
BusyBox is copyrighted by many authors between 1998-2012.
Licensed under GPLv2. See source distribution for detailed
copyright notices.

Usage: busybox [function [arguments]...]
   or: busybox --list[-full]
   or: busybox --install [-s] [DIR]
   or: function [arguments]...

	BusyBox is a multi-call binary that combines many common Unix
	utilities into a single executable.  Most people will create a
	link to busybox for each function they wish to use and BusyBox
	will act like whatever it was invoked as.

Currently defined functions:
	[, [[, acpid, adjtimex, ar, arp, arping, ash, awk, base64, basename,
	bbconfig, beep, blkid, blockdev, bootchartd, brctl, bunzip2, bzcat,
	bzip2, cal, cat, catv, chat, chattr, chgrp, chmod, chown, chpst,
	chroot, chrt, chvt, cksum, clear, cmp, comm, cp, cpio, crond, crontab,
	cttyhack, cut, date, dc, dd, deallocvt, depmod, devmem, df, dhcprelay,
	diff, dirname, dmesg, dnsd, dnsdomainname, dos2unix, dpkg, dpkg-deb,
	du, dumpkmap, dumpleases, echo, ed, egrep, env, envdir, envuidgid,
	ether-wake, expand, expr, fakeidentd, false, fbset, fbsplash, fdflush,
	fdformat, fdisk, fgconsole, fgrep, find, findfs, flash_lock,
	flash_unlock, flashcp, flock, fold, free, freeramdisk, fsck,
	fsck.minix, fsync, ftpd, ftpget, ftpput, fuser, getopt, grep, groups,
	gunzip, gzip, halt, hd, hdparm, head, hexdump, hostname, httpd, hush,
	hwclock, id, ifconfig, ifdown, ifup, inetd, init, inotifyd, insmod,
	install, ionice, iostat, ip, ipaddr, ipcalc, ipcrm, ipcs, iplink,
	iproute, iprule, iptunnel, kbd_mode, kill, killall, killall5, klogd,
	less, linuxrc, ln, loadkmap, logread, losetup, lpd, lpq, lpr, ls,
	lsattr, lsmod, lsof, lspci, lsusb, lzcat, lzma, lzop, lzopcat,
	makedevs, makemime, man, md5sum, mdev, mesg, microcom, mkdir, mkdosfs,
	mke2fs, mkfifo, mkfs.ext2, mkfs.minix, mkfs.reiser, mkfs.vfat, mknod,
	mkswap, mktemp, modinfo, modprobe, more, mount, mountpoint, mpstat, mv,
	nameif, nanddump, nandwrite, nbd-client, nc, netstat, nice, nmeter,
	nohup, nslookup, od, openvt, patch, pgrep, pidof, ping, ping6,
	pipe_progress, pivot_root, pkill, pmap, popmaildir, poweroff, powertop,
	printenv, printf, ps, pscan, pstree, pwd, pwdx, raidautorun, rdate,
	rdev, readlink, readprofile, realpath, reboot, reformime, renice,
	reset, resize, rev, rm, rmdir, rmmod, route, rpm, rpm2cpio, rtcwake,
	run-parts, runsv, runsvdir, rx, script, scriptreplay, sed, sendmail,
	seq, setconsole, setkeycodes, setlogcons, setserial, setsid, setuidgid,
	sh, sha1sum, sha256sum, sha3sum, sha512sum, showkey, slattach, sleep,
	smemcap, softlimit, sort, split, start-stop-daemon, stat, strings,
	stty, sum, sv, svlogd, swapoff, swapon, switch_root, sync, sysctl,
	syslogd, tac, tail, tar, tcpsvd, tee, telnet, telnetd, test, tftp,
	tftpd, time, timeout, top, touch, tr, traceroute, traceroute6, true,
	tty, ttysize, tunctl, tune2fs, ubiattach, ubidetach, ubimkvol,
	ubirmvol, ubirsvol, ubiupdatevol, udhcpc, udhcpd, udpsvd, umount,
	uname, uncompress, unexpand, uniq, unix2dos, unlzma, unlzop, unxz,
	unzip, uptime, usleep, uudecode, uuencode, vconfig, vi, volname, watch,
	watchdog, wc, wget, which, whoami, whois, xargs, xz, xzcat, yes, zcat,
	zcip