Servo AutoTest framework and pwr_button test.

BUG=chromium-os:16588
TEST=manually tested with servo and partner device

Change-Id: I1a89b60203c511ff716ba16cdea986dcfbe53659
Reviewed-on: http://gerrit.chromium.org/gerrit/3098
Reviewed-by: <craigdh@google.com>
Tested-by: <craigdh@google.com>
Reviewed-by: Nirnimesh <nirnimesh@chromium.org>
5 files changed