r7456: Add a simple type that represents a pointer. The ejs people may ask us

r7456: Add a simple type that represents a pointer.  The ejs people may ask us
to change this later but that will be pretty easy.

We can use this type to pass around pointers to handles in C.  Talloc
allows us to do type checking too.
(This used to be commit b95c0bc9b0a18aeaa89f704e37669f01df2c2ad0)