Reorder __init__.py layout to improve API reference documentation

The documentation is ordered alphabetically, however we have the choice to force it to order by source (using directive `:member-order: bysource`). 

@mrpollo  Propose for discussion is that the source in **init**.py be re-ordered such that the things we want people to use are first - ie 

```
local_connect()
APIConnection
Vehicle
.. don't care
web_connect
AuthInfo
Mission
```
