use publishedDate from feed to determine if we need to handle feed entries or not

src/main/java/com/commafeed/backend/model/Feed.java

@@ -45,6 +45,12 @@ public class Feed extends AbstractModel {
 	@Index(name = "lastupdated_index")
 	private Date lastUpdated;
 
+	/**
+	 * Last publishedDate value in the feed
+	 */
+	@Temporal(TemporalType.TIMESTAMP)
+	private Date lastPublishedDate;
+
 	/**
 	 * Last time we successfully refreshed the feed
 	 */
@@ -210,4 +216,12 @@ public class Feed extends AbstractModel {
 		this.pushLastPing = pushLastPing;
 	}
 
+	public Date getLastPublishedDate() {
+		return lastPublishedDate;
+	}
+
+	public void setLastPublishedDate(Date lastPublishedDate) {
+		this.lastPublishedDate = lastPublishedDate;
+	}
+
 }