constructor() {
        this.defaults = {
            name            : null,     // name for the overlay, otherwise input id is used
            html            : '',       // text or html
            style           : '',       // additional style for the overlay
            class           : '',       // add class for w2ui-tooltip-body
            position        : 'top|bottom',   // can be left, right, top, bottom
            draggable       : false,    // if true, then tooltip can be move with mouse
            align           : '',       // can be: both, both:XX left, right, both, top, bottom
            anchor          : null,     // element it is attached to, if anchor is body, then it is context menu
            contextMenu     : false,    // if true, then it is context menu
            anchorClass     : '',       // add class for anchor when tooltip is shown
            anchorStyle     : '',       // add style for anchor when tooltip is shown
            autoShow        : false,    // if autoShow true, then tooltip will show on mouseEnter and hide on mouseLeave
            autoShowOn      : null,     // when options.autoShow = true, mouse event to show on
            autoHideOn      : null,     // when options.autoShow = true, mouse event to hide on
            arrowSize       : 8,        // size of the carret
            screenMargin    : 2,        // min margin from screen to tooltip
            autoResize      : true,     // auto resize based on content size and available size
            margin          : 1,        // distance from the anchor
            offsetX         : 0,        // delta for left coordinate
            offsetY         : 0,        // delta for top coordinate
            maxWidth        : null,     // max width
            maxHeight       : null,     // max height
            watchScroll     : null,     // attach to onScroll event // TODO:
            watchResize     : null,     // attach to onResize event // TODO:
            hideOn          : null,     // events when to hide tooltip, ['click', 'change', 'key', 'focus', 'blur'],
            onThen          : null,     // called when displayed
            onShow          : null,     // callBack when shown
            onHide          : null,     // callBack when hidden
            onUpdate        : null,     // callback when tooltip gets updated
            onMove          : null      // callback when tooltip is moved
        }
    }
Part of w2ui 2.0 library
- Dependencies: mQuery, w2utils, w2base

TODO:
- need help pages

2.0 Changes
- multiple tooltips to the same anchor
- options.contextMenu
- options.prefilter - if true, it will show prefiltered items for w2menu, otherwise all
- menu.item.help, menu.item.hotkey, menu.item.extra
- options.selected -> for w2menu
- options.tooltip => {}
- w2menu event onTooltip
- added onMouseEnter and onMouseLeave for w2menu