Split Modem into ModemClassic and Modem1

Along the way:

  Restructure ModemManagerXxx to use the split modem classes.

  Add new mocks to limit scope of modem tests

  Change modem state enum to a neutral format and convert from MM1 and
  MMClassic to this format.

  Fix a bug where we weren't properly releasing a callback in
  DBusObjectManagerProxy.

  Add new DBus property matchers

BUG=chromium-os:27935,chromium-os:27936
TEST=unit tests

Change-Id: Ib78c7dfd9e30fe556f09a4427fd71c9d785210c9
Reviewed-on: https://gerrit.chromium.org/gerrit/19228
Commit-Ready: David Rochberg <rochberg@chromium.org>
Reviewed-by: David Rochberg <rochberg@chromium.org>
Tested-by: David Rochberg <rochberg@chromium.org>
diff --git a/mock_dbus_objectmanager_proxy.h b/mock_dbus_objectmanager_proxy.h
index fa6530e..07d6e02 100644
--- a/mock_dbus_objectmanager_proxy.h
+++ b/mock_dbus_objectmanager_proxy.h
@@ -24,6 +24,7 @@
       void(const InterfacesAddedSignalCallback &callback));
   MOCK_METHOD1(set_interfaces_removed_callback,
       void(const InterfacesRemovedSignalCallback &callback));
+  void IgnoreSetCallbacks();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(MockDBusObjectManagerProxy);