[css-flexbox] Update DoC

--HG--
extra : rebase_source : 69eb234182f12da293f221ddc4450d9325741aa2
[css-flexbox] Minor errors <http://lists.w3.org/Archives/Public/www-style/2014Feb/0469.html>

--HG--
extra : rebase_source : 16325ca7b230012f82803303890b1147f27712b5
[css-flexbox] Add Peter Moulder to acknowledgements