LESS Scanner

[thybzi]

Please add a scanner for one more CSS preprocessor named LESS: http://lesscss.org

Like SCSS (see #137, #93), LESS has CSS-like syntax with some specific "extensions".

CSS syntax highlighting isn't suitable for LESS, because it doesn't concern these "extensions", e.g.:

1. Ampersands (&, meaning "parent selector") are destructed (shown as x%x%)
2. Subselectors are not highlighted as selectors
3. Variables, mixins and functions aren't accounted
4. LESS-style comments (// this kind, I mean) are ignored
5. And so on

Example of LESS code:

/* CSS-style comment for mixin */
.border-radius(@value: 5px) {
    -moz-border-raduis: @value;
    -webkit-border-raduis: @value;
    border-raduis: @value;
}

.parent {
    @base-color: #ffc; // variable (LESS-style comment)
    .border-radius(); // mixin call without params
    -ms-filter: 'progid:DXImageTransform.Microsoft.gradient(startColorstr=@{base-color},endColorstr=@{base-color})'; // string with variable interpolation

    & > .child {
        color: @base-color;
        .border-radius(); // mixin call without params and braces
        width: ~"expression(this.parentNode.offsetWidth + 'px')"; // syntax escaping
    }

    &.subclass {
        background-color: lighten(@base-color, 10%); // function call
        .border-radius(10px); // mixin call with params
    }
}