Make opentxsproto Python bindings behave more like a Python package
Make opentxsproto Python bindings behave more like a Python package

Currently, the `opentxsproto` directory needs to go on your Python `PATH`; this isn't very Pythonic. This PR rewrites *Protobuf-generated* files to switch from unqualified `import Foo_pb2` to `import opentxsproto.Foo_pb2`. Usage is then:

```python
import opentxsproto

br = opentxsproto.BailmentReply_pb2.BailmentReply()
```

Without a modified `__init__.py`, `from opentxsproto import *` won't work. This PR also generates an `__init__.py` which in turn imports each binding file into the `opentxsproto` namespace. You can still use the style above, but it also allows:

```python
import opentxsproto as pb

br = pb.BailmentReply()
```

Ultimately, some kind of change to how the Protobuf compiler is invoked seems necessary, but this works for now.

The version number is bumped.

Open-Transactions/opentxs-proto,justusranvier/opentxs-proto,justusranvier/opentxs-proto,Open-Transactions/opentxs-proto