Add stacktrace to ParseError

Fixes #854. Also clean up the parse error test a little, while adding a .stack check.
I know it's should be supported in IE >= 10, that's why I said it'll fail in IE < 10 at first.

>Do you mind telling me what the error is exactly?

Qunit fails because ```error.stack``` is ```undefined```.

I tried to run the code from MSDN and it works:
```
try
    {
        var x = y.name;
    }
catch(e)
    {
        document.write ("Error stack: ")
        document.write (e.stack);
    }
```
Hmm...