Added feature to prevent duplicate registration

If exclude list parameter is provided during the registration process,
then all the devices are checked for duplicate registration by calling
'check-only' sign to device. If any one of the device response with
success, this means that there is duplicate registration and process is
terminated after waiting for user presence verification and response
code U2fReturnCode::CONDITIONS_NOT_SATISFIED is returned to the caller.
If all devices pass the duplication registration check, then we proceed
to normal registration process.

Bug: 664630
Change-Id: Iaa70490084c7086185e721b5e22d30f73ee9b66d
Reviewed-on: https://chromium-review.googlesource.com/739927
Commit-Queue: Jun Choi <hongjunchoi@chromium.org>
Reviewed-by: Reilly Grant <reillyg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#515041}
11 files changed