shill: Add uint64 properties

This is a fairly minimal addition, since we will only need
read-only derived types.

BUG=chromium-os:31584
TEST=New unit tests; list-devices on a real machine

Change-Id: I7b65224ae329443066f563b620b379f29006f8a0
Reviewed-on: https://gerrit.chromium.org/gerrit/27157
Reviewed-by: Paul Stewart <pstew@chromium.org>
Tested-by: Paul Stewart <pstew@chromium.org>
Commit-Ready: Paul Stewart <pstew@chromium.org>
diff --git a/accessor_interface.h b/accessor_interface.h
index 527204c..50dab1e 100644
--- a/accessor_interface.h
+++ b/accessor_interface.h
@@ -75,6 +75,7 @@
 typedef std::tr1::shared_ptr<AccessorInterface<uint8> > Uint8Accessor;
 typedef std::tr1::shared_ptr<AccessorInterface<uint16> > Uint16Accessor;
 typedef std::tr1::shared_ptr<AccessorInterface<uint32> > Uint32Accessor;
+typedef std::tr1::shared_ptr<AccessorInterface<uint64> > Uint64Accessor;
 
 }  // namespace shill