Backup management from Paper plugin moved into Pandalib + new BackupCleaner + refactored working directory backup

pandalib-paper/pom.xml

@@ -70,6 +70,13 @@
             <artifactId>paper-mojangapi</artifactId>
             <version>${paper.version}-SNAPSHOT</version>
         </dependency>
+
+        <!-- Cron expression interpreter -->
+        <dependency>
+            <groupId>ch.eitchnet</groupId>
+            <artifactId>cron</artifactId>
+            <version>1.6.2</version>
+        </dependency>
     </dependencies>
 
 </project>