Assigns options to the internal options object, and provides defaults.
@param {Object} opts - Options object
function _applyRemainingDefaultOptions(opts) {
      opts.icon = opts.hasOwnProperty('icon') ? opts.icon : '\ue9cb'; // Accepts characters (and also URLs?), like  '#', '¶', '❡', or '§'.
      opts.visible = opts.hasOwnProperty('visible') ? opts.visible : 'hover'; // Also accepts 'always' & 'touch'
      opts.placement = opts.hasOwnProperty('placement')
        ? opts.placement
        : 'right'; // Also accepts 'left'
      opts.class = opts.hasOwnProperty('class') ? opts.class : ''; // Accepts any class name.
      // Using Math.floor here will ensure the value is Number-cast and an integer.
      opts.truncate = opts.hasOwnProperty('truncate')
        ? Math.floor(opts.truncate)
        : 64; // Accepts any value that can be typecast to a number.
    }