1、fix bugs

2、add setEmptyHint , getEmptyHint method

Author: qstumn

gradle/wrapper/gradle-wrapper.properties

@@ -1,6 +1,6 @@
-#Tue Aug 16 09:07:01 CST 2016
+#Thu Mar 16 09:13:43 CST 2017
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-2.14.1-all.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-3.3-all.zip