evaluate whether to change device path selection

[merge]

Should we move path selection for device open out of the hands of the library user?

Input knows it's to work with input devices, and most other input_raw plugins
have some idea of what devices they should be working with. Perhaps we should
move that into a new callback in the raw plugins.

But in any case we should make an informed decision going forward.

[merge]

There's a related problem description on stackoverflow: https://stackoverflow.com/questions/11437435