Segmentation fault when incorrectly instantiating a new Date

```
What steps will reproduce the problem?
import PyV8
c = PyV8.JSContext()
c.enter()
c.eval('new Date("null")')

What is the expected output? What do you see instead?
Expect to see some sort of exception. Instead the program seg faults.

What version of the product are you using? On what operating system?
From PyPI 1.0-dev on Debian 7.8.
```

Original issue reported on code.google.com by `t...@rewardstyle.com` on 2 Apr 2015 at 3:20