This is the v2 branch which only supports EV3. Removing the extra APIs
will prevent them from showing up when this library is used for code
completion.
Intellisense in VS Code (both jedi and ms python language server) picks
up all imported names and suggests them with equal priority for
code completion. By adding a leading underscore, intellisense lists
these with a lower priority, so they don't get in the way.
Also rename from builtins to _common while we are touching this to
better reflect the intention of the module (it contains types shared
by multiple modules, not builtin types like int).
Because this module describes devices that can be built into a hub or other device.
Since this design is now explicitly shown in
the docs as well, we don't need to hide this
module in the package.