fix UPPER and LOWER
fix UPPER and LOWER

i kept getting TypeError: y.toUpperCase is not a function,

my temp fix is overwriting the function like so:
alasql.fn.UPPER = function(s) {
  return String(s).toUpperCase();
}

This should fix it at the source.
kanghj/alasql,kanghj/alasql,kanghj/alasql,agershun/alasql,agershun/alasql,agershun/alasql,agershun/alasql