add .bash_profile and .bashrc when build user
[Makefile] remove variable 'toolsenv' and 'toolsbash'
refactor target binutils-prebuild
refactor binutils/Makefile and remove target binutils-stage3
rename root.ext2 to root.img
format root.img as ext3
Dont' install /tools/bin when MKTREE, and don't link bash into
/tools/bin/sh.
remove variable 'WGET'
Architecture related changes.
Merge branch 'master' of github.com:qiuhw/lfs-livecd

Conflicts:
	Makefile