JsArrayList.contains() doesn't work in IE8 #4

Evidently IE 8 and earlier is missing Array.indexOf() which causes JsArrayList.contains() to break.

Fix was simple once I figured out what was going on. Maybe this could be included in the implementation.

<script> if (!Array.prototype.indexOf) { Array.prototype.indexOf = function(elt /*, from*/) { var len = this.length >>> 0; var from = Number(arguments[1]) || 0; from = (from < 0) ? Math.ceil(from) : Math.floor(from); if (from < 0) from += len; for (; from < len; from++) { if (from in this && this[from] === elt) return from; } return -1; }; } </script>