Support dconf 0.13.4

TEST=Manually

Review URL: https://codereview.appspot.com/6426044

Conflicts:
	conf/dconf/config-private.h
	conf/dconf/config.h
	dconf/config.h
Merge pull request #7 from microcai/1.4.y

back port 1.5.y "Support dconf 0.13.4" to 1.4.y, please provide new ibus-1.4.3 tarball :)