Move mbox to var/
.emacs: soft tabs
Add composer bin to $PATH
Fix the issue that "rm 1" failed

In common.sh, rm is aliased to "rm -iv ", and in
oh-my-zsh/lib/directories.zsh, 1 is aliased to "cd -", So "rm 1"
becomes "rm -iv cd -" due to the tailing space in rm's alias, which
indicates alias expansion of following components