Refactor Bluetooth HID Mouse API

A nice, new, separated API for emulating a mouse is now here.
Kit redirection is explicit in it, too. This represents the first step
in ridding ourselves of the getattr hack and solving
http://crbug.com/764055 .
RN42 can now keep holding buttons while scrolling, too!

Remove the old HID keyboard/mouse API from the public interface in
PeripheralKit, and remove the pylint silencer on BluefruitLE.

The RN42 no longer clamps values to [-127,127]. The API is no longer
publicly exposed, so we're handling those checks elsewhere.

BUG=chromium:752719,chromium:764055
TEST=Run this code on the Chameleon board, with an RN42 attached:
$ make && make remote-install CHAMELEON_HOST=$CHAMELEON_IP
Execute the non-flaky non-stress tests that use this code,
see that the tests pass:
$ test_that --board ${BOARD} --args "chameleon_host=${CHAMELEON_IP}" \
${DUT_IP} bluetooth_AdapterPairing.mouse \
bluetooth_AdapterPairing.mouse.pairing_twice \
bluetooth_AdapterHIDReports.mouse

Change-Id: I07b70f0c5fba4abde34f640199f7ccf4c916224d
Reviewed-on: https://chromium-review.googlesource.com/663788
Commit-Ready: Alexander Lent <alent@google.com>
Tested-by: Alexander Lent <alent@google.com>
Reviewed-by: Wai-Hong Tam <waihong@google.com>
Reviewed-by: Shyh-In Hwang <josephsih@chromium.org>
4 files changed