code: function toBooleanInt (val) {
      var type = typeof val
      // boolean
      if (type === 'boolean') {
          return val ? '1' : '0'
      }
      // string
      else if (type === 'string') {
          // true and 1 are only true string values
          return val === 'true' || val === '1' ? '1' : '0'
      }
      // number
      else if (type === 'number') {
          // 1 or greater is true
          return val >= 1 ? '1' : '0'
      }
      // all other values false
      else {
          return '0'
      }
  
  }
docs: @function toBooleanInt
  
  convert various values to a boolean integer (0|1)
  
  @param {any} val
  
  @returns {integer}