Create SVG element. -------------------
function createElement(el, attrs, children) {

        if (!el) return undefined;
        
        // If `el` is an object, it is probably a native SVG element. Wrap it to VElement.
        if (typeof el === 'object') {
            return new VElement(el);
        }
        attrs = attrs || {};

        // If `el` is a `'svg'` or `'SVG'` string, create a new SVG canvas.
        if (el.toLowerCase() === 'svg') {
            
            attrs.xmlns = ns.xmlns;
            attrs['xmlns:xlink'] = ns.xlink;
            attrs.version = SVGversion;
            
        } else if (el[0] === '<') {
            // Create element from an SVG string.
            // Allows constructs of type: `document.appendChild(Vectorizer('<rect></rect>').node)`.
            
            var svg = '<svg xmlns="' + ns.xmlns + '" xmlns:xlink="' + ns.xlink + '" version="' + SVGversion + '">' + el + '</svg>';
            var parser = new DOMParser();
            parser.async = false;
            var svgDoc = parser.parseFromString(svg, 'text/xml').documentElement;

            // Note that `createElement()` might also return an array should the SVG string passed as
            // the first argument contain more then one root element.
            if (svgDoc.childNodes.length > 1) {

                return _.map(svgDoc.childNodes, function(childNode) {

                    return new VElement(document.importNode(childNode, true));
                });
            }
            
            return new VElement(document.importNode(svgDoc.firstChild, true));
        }
        
        el = document.createElementNS(ns.xmlns, el);

        // Set attributes.
        for (var key in attrs) {

            setAttribute(el, key, attrs[key]);
        }
        
        // Normalize `children` array.
        if (Object.prototype.toString.call(children) != '[object Array]') children = [children];

        // Append children if they are specified.
        var i = 0, len = (children[0] && children.length) || 0, child;
        for (; i < len; i++) {
            child = children[i];
            el.appendChild(child instanceof VElement ? child.node : child);
        }
        
        return new VElement(el);
    }