Add ISSUE_COMMENT.ACTION column.

This column will be stored 'open', 'reopen' or NULL.

src/main/resources/update/1_0.sql

@@ -51,6 +51,7 @@ CREATE TABLE ISSUE_COMMENT(
 		REPOSITORY_NAME VARCHAR(100) NOT NULL,
 		ISSUE_ID INT NOT NULL,
 		COMMENT_ID INT AUTO_INCREMENT,
+		ACTION VARCHAR(10),
 		COMMENTED_USER_NAME VARCHAR(100) NOT NULL,
 		CONTENT TEXT NOT NULL,
 		REGISTERED_DATE TIMESTAMP NOT NULL,