グラフ使ってみるテスト。
Merge remote-tracking branch 'origin/user/imo' into conflict_resolve
Merge remote-tracking branch 'origin/user/imo' into conflict_resolve
グラフ表示に関するクラスを追加。
Merge remote-tracking branch 'origin/conflict_resolve' into user/imo

Conflicts:
	res/layout/activity_today.xml
	src/com/example/mytai_imo/TodayActivity.java