touchscreen_calibration: use an arduino serial device to control test fixture

This patch fixes the following issues:
- uses an arduino serial device to control the fixture
- replaces the original SafeSerialController class by FixtureSerialDevice
- simplifies the probe actions
- moves the WriteSysfs()s into methods of DebugDataReader
- replaces all GPIO and registers actions by higher level APIs
- simplifies the callback events and modifies .js and .html accordingly.

BUG=chrome-os-partner:23254
TEST=Manually on DUT. The test flow must proceed smoothly until
PASS/FAILURE is prompted as the test result.

Change-Id: I2748a9a54a8c95f45d5975c074b3ff08f46e024d
Reviewed-on: https://chromium-review.googlesource.com/173193
Reviewed-by: Shyh-In Hwang <josephsih@chromium.org>
Commit-Queue: Shyh-In Hwang <josephsih@chromium.org>
Tested-by: Shyh-In Hwang <josephsih@chromium.org>
3 files changed