comments within a rule break to_css

[stevenharman]

I discovered this issue while trying to import a jQuery UI Theme, like so:

@import "jquery-ui-1.7.2.custom.css";

The import fails when it hits an IE6 hack that uses comments within a css rule. The offending rule looks like:

.ui-datepicker-cover {
    display/**/: block; /*sorry for IE5*/
}

The custom theme css can be downloaded from http://jqueryui.com/themeroller/

[stevenharman]

I think I have a fix ready for this over at http://github.com/stevenharman/less/tree/issue-155