Differently from Windows, this call seems to work
appropriately for Linux.
Enabling it resolves the issue of the device handle
being busy when trying to reopen the same handle.

Some Pupil Labs cameras apparently ship with non-unique productId.
Using just the product name instead.

When using 640x480 @ 120 FPS and the processing can't keep up with
the frame rate, some glitches start showing in the images; these commit
adds some additional options that were used during test and might be
useful in the future.

I'm not entirely sure where these glitches come from, but it seems they originate
within libuvc.
After tracing it back to this point, increasing
LIBUVC_NUM_TRANSFER_BUFS  seems to get rid of the bug.
However, setting it too high impedes opening all three pupil cameras.

Temporary solution is to make sure processing can keep up with the
framerate (e.g., by downsizing the processing input in EyeRecToo).

Original value came from pupil source; however, that results in a gray image

When testing selecting different cameras online, a problem with the device
handle was found: after closing the stream, we can successfully reopen it
but never get frames. This commit works around that issue.

When experimenting with multiple cameras on separate threads sometimes
uvc_open would return UVC_ERROR_NOT_FOUND.