[Vimoutliner] problem with plugin loading code

[Martin DeMello]

I'm running vim 7.1.213 and vimoutliner 0.34 under Gentoo, both
installed from portage. In order to get vimoutliner working, I had to
go to  /usr/share/vim/vimfiles/ftplugin/vo_base.vim and comment out
everything from

" let s:tmp = g:vo_modules_load . ':'

onwards, otherwise it complains about g:vo_modules_load being unknown.
Grepping through /usr/share/vim confirmed that it was indeed not
defined anywhere. Am I missing a file?

martin