This updates the packet header so that the encryption byte flag is now
32 bits. This also updates the powershell and python extensions so that
both of the bindings work correctly as a result of the TLV packet header
changes.
The package script was (stupidly) written (by me) to replace '\\' with
'.' when generating python import module names. Of course, this works
great on windows, but it means if you generate the package on linux
things break horribly. The result was that the latest package wouldn't
resolve anything useful when importing key stuff like ctypes or pty.
This PR fixes the issue so that the modules are correctly wired in
regardless of the OS that the package was constructed on.
This commit includes code that was missing from the original Python PR which adds support for the multiprocessing module in Python. I have no idea why this was missed, but it was. The code also includes adjustments to the loader which attempts to resolve modules appropriately based on name. This is a bit of a kludge thanks to the way that Python module resolution hooks work, as it's not clear exactly which namespace the module is intended to be loaded from at runtime as it's not passed to the resolver. Down the track we may need to get smarter with the resolver so that we have a per-module resolver (ie. a tree of resolvers).
