JS codegen improvements; barely usable now

tests/js/test1.nim

@@ -0,0 +1,23 @@
+discard """
+  cmd: "nimrod js --hints:on $# $#"
+  output: "1261129"
+"""
+
+# This file tests the ECMAScript generator
+
+import
+  dom, strutils
+
+var
+  inputElement = "1123"
+
+proc OnButtonClick(inputElement: string) {.exportc.} =
+  let v = $inputElement
+  if v.allCharsInSet(whiteSpace):
+    echo "only whitespace, hu?"
+  else:
+    var x = parseInt(v)
+    echo x*x
+
+onButtonClick(inputElement)
+