add translateType method

app/src/main/java/org/cutem/cutecalendar/model/TodoItemUtil.java

@@ -372,4 +372,23 @@ public class TodoItemUtil {
         return !isBeforeStart(item) && !isEnded(item);
     }
 
+    private static String[] TYPE_NAME = {
+            "unknown",
+            "others",
+            "conference",
+            "date",
+            "trip",
+            "anniversary",
+            "course",
+            "interview"
+    };
+
+    public static String translateType(int type) {
+        if (1 <= type && type < TYPE_NAME.length) {
+            return TYPE_NAME[type];
+        } else {
+            return TYPE_NAME[0];
+        }
+    }
+
 }