This change includes a lot more functionality. Enough to actually
run the webserver-py example through previews, updates, and destroys!
* Actually wire up the gRPC connections to the engine/monitor.
* Move the Node.js and Python generated Protobuf/gRPC files underneath
the actual SDK directories to simplify this generally. No more
copying during `make` and, in fact, this was required to give a smoother
experience with good packages/modules for the Python's SDK development.
* Build the Python egg during `make build`.
* Add support for program stacks. Just like with the Node.js runtime,
we will auto-parent any resources without explicit parents to a single
top-level resource component.
* Add support for component resource output properties.
* Add get_project() and get_stack() functions for retrieving the current
project and stack names.
* Properly use UNKNOWN sentinels.
* Add a set_outputs() function on Resource. This is defined by the
code-generator and allows custom logic for output property setting.
This is cleaner than the way we do this in Node.js, and gives us a
way to ensure that output properties are "real" properties, complete
with member documentation. This also gives us a hook to perform
name demangling, which the code-generator typically controls anyway.
* Add package dependencies to setuptools.py and requirements.txt.
