Added variable @iconPrefix with value "icon-" to handle the prefix because in Joomla 3.0 there are conflicts with the prefix, so you can change only the prefix at once in variables.less

(I'm developing a plugin for Joomla 3.x and generate css from less with Grunt included FontAwsome)

It is also working with scss => http://stackoverflow.com/questions/17302333/add-prefixes-to-css-class-names-using-less-or-sass

If it is a good idea I can rewrite scss, too. Write me at mail@novusidea.de