tools: evemu-device: rely on libevdev to retrieve the device node

Cleanup a little evemu-device now that we rely on libevdev for the internal
stuffs.
Needs to export a new function evemu_get_devnode, but we already have
broken the ABI.

Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>
tools: evemu-device: replace spaces by tabs

Tabs are used throughout the tools .c files, so fix that.

Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>
tools: device: rely on libevdev to open the uinput node

libevdev can take care of the uinput node, I am glad to remove this part.

In order to hide the libevdev dependency and all the problems that may occurs,
add a new function evemu_create_managed to the API so that clients can benefit
from this functionality.

Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>