JDK 1.7 默认现在显示 RSA 的签名字符串了，用选项-v可以显示出MD5的签名。
keytool -v -list -alias wxkdebugkey -keystore my-release-key.keystore
To see a world in a grain of sand.
And a heaven in a wild flower
Hold infinity in the palm of your hand.
And eternity in an hour
一花一世界
一沙一天堂
掌中握无限
霎那成永恒
