ibus-xkb-layouts: Support ibus-1.4.

I've confirmed it could compile with the new API, but I haven't checked if it works correctly.

BUG=chromium-os:9810
TEST=manually

Change-Id: I22103e7d91aa1216699701d9c9cfe8f2597068a9

Review URL: http://codereview.chromium.org/5449001
2 files changed