Remove import * statement in renderer, just bind to different name.
pep8-ify renderer.py after changes.
Remove the `import *`. Explicitly import what we want to expose.

Before __all__ was used to manage these. But it's clearer to
just import what we want users to see.
Force error on `import *` from the .py file. Update tests.

We *want* users to be able to do:

```python
from plotly.graph_objs import *
```

NO ONE should do:

```python
from plotly.graph_objs.graph_objs import *
```

The former is a nicely-controlled namespace. The latter is not.
Remove `import *`. Replace with explicit public interface.
Don't let anyone `import *` plotly.plotly.plotly ever again...

It'd be nice to not let folks `import *` plotly.plotly, but that's
a little overkill and perhaps actually useful for fiddling.
Merge pull request #119 from plotly/andrew-remove-import-all

Andrew remove import all