Add further getters, converting the data to other units

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/model/CalendarEvents.java

@@ -99,6 +99,10 @@ public class CalendarEvents {
             return begin;
         }
 
+        public int getBeginSeconds() {
+            return (int)(begin/1000);
+        }
+
         public long getEnd() {
             return end;
         }
@@ -107,6 +111,14 @@ public class CalendarEvents {
             return end - begin;
         }
 
+        public int getDurationSeconds() {
+            return (int)((getDuration())/1000);
+        }
+
+        public short getDurationMinutes() {
+            return (short)(getDurationSeconds()/60);
+        }
+
 
         public long getId() {
             return id;