No way to get stack trace from javascript TypeError or ReferenceError

```
Run something like the following:

import PyV8
c = PyV8.JSContext()
c.enter()
c.eval("function f(){foo = null; foo.bar();};")
c.eval("f()")

The resulting exception shows the line of the error, but there appears to be no
way to get the full stack trace (like there would be if the code was something
like 'throw Error()')

```

Original issue reported on code.google.com by `russell....@gmail.com` on 4 Jun 2013 at 12:29

Reproduce the issue through PyV8.JSContext and its c.eval calls using the supplied TypeError and ReferenceError examples. Trace how those exceptions are exposed after c.eval("f()"), then compare their information with a thrown Error; done means both errors provide a full stack trace.

Written by the indexing model from the issue text.