CSS, Colibri skin (and probaly other) gradient support in Opera

Opera also supports gradient for quite a while
http://dev.opera.com/articles/view/css3-linear-gradients/#comments

http://localhost:8888/XWiki/bin/skin/skins/colibri/colibri.css?colorTheme=ColorThemes.DefaultColorTheme
contains a few statements.

background-image: -moz-linear-gradient(top, #3A8ABC 0%, #0272A6 50%);
background-image: -webkit-linear-gradient(top, #3A8ABC 0%, #0272A6 50%);
background-image: -ms-linear-gradient(top, #3A8ABC 0%, #0272A6 50%);
background-image: linear-gradient(top, #3A8ABC 0%, #0272A6 50%);

adding
background-image: -o-linear-gradient(top, #3A8ABC 0%, #0272A6 50%);

should fix it.

Also less.js probably could make compatibility efforts easier http://lesscss.org