Built-in objects not accessible via the global object

```
What steps will reproduce the problem?

import PyV8

class Global(PyV8.JSClass):

def __init__(self):
self.s = self

def write(self, val):
print val

with PyV8.JSContext(Global()) as ctx:
ctx.eval("""
write(String)
write(s.String)
""")

What is the expected output? What do you see instead?

Output is: None/Undefined
Should output: function String() { [native code] }

```

Original issue reported on code.google.com by `ATM1...@gmail.com` on 14 Feb 2011 at 4:00