seek into file-like for ipc

[castironpi at gmail.com]

Hive:

How about a shared-memory/file-map to a Python object?  Seek and
tell.  Has its own GIL?  Raises Exceptions?

Standard C++ prohibits returning pointer-to-members.  File runs in its
own thread, can callback host and raise its own exceptions, iow file
process.

Think live persistence.

Client side producer proxies / delegates to the object.  Ready, Go!