lorgnette: Initial working code

Initial daemon is working, and provides a DBus service over which
one can do a "ListScanners" call.

BUG=chromium:239087
TEST=Emerge using using as-yet-to-be-installed ebuild
dbus-send --system --print-reply --fixed --dest=org.chromium.lorgnette \
   /org/chromium/lorgnette/Manager org.chromium.lorgnette.Manager.ListScanners

Change-Id: I74856f343d68ecc3ff897e753e0dfca7398f47a0
Reviewed-on: https://gerrit.chromium.org/gerrit/56310
Reviewed-by: mukesh agrawal <quiche@chromium.org>
Tested-by: Paul Stewart <pstew@chromium.org>
Commit-Queue: Paul Stewart <pstew@chromium.org>
10 files changed