problem and solve:
1. vim can't autocomplete spell, and report error like:_vim_files: function definition file not found, so does rvm when iterm2 starting.
2. google it and try to use the commonest advice: rm ~/.zcompdump*, no use, and there isn't any file like that
3. brew uninstall autojump, and then vim & rvm are all good.
4. finally, brew install autojump, again
5. all be right
