Re-throw callback errors on nextTick

Otherwise an error thrown in a callback would be throw on the parser's stack.

lib/parser/javascript.js

@@ -1,5 +1,10 @@
 /*global Buffer require exports console setTimeout */
 
+// TODO - incorporate these V8 pro tips:
+//    pre-allocate Arrays if length is known in advance
+//    do not use delete
+//    use numbers for parser state
+
 var events = require("events"),
     util = require("../util").util;