Clear up the event path when starting up the old and new persisters

The new persister won't load anything until the old one has finished

core/src/main/groovy/com/muwire/core/Core.groovy

@@ -1,5 +1,6 @@
 package com.muwire.core
 
+import com.muwire.core.files.PersisterDoneEvent
 import com.muwire.core.files.PersisterFolderService
 
 import java.nio.charset.StandardCharsets
@@ -262,7 +263,7 @@ public class Core {
 
         log.info "initializing folder persistence service"
         persisterFolderService = new PersisterFolderService(new File(home, "files"), eventBus)
-        eventBus.register(UILoadedEvent.class, persisterFolderService)
+        eventBus.register(PersisterDoneEvent.class, persisterFolderService)
         eventBus.register(UIPersistFilesEvent.class, persisterFolderService)
         eventBus.register(FileHashedEvent.class, persisterFolderService)
         eventBus.register(FileUnsharedEvent.class, persisterFolderService)

core/src/main/groovy/com/muwire/core/files/PersisterDoneEvent.groovy

@@ -0,0 +1,12 @@
+package com.muwire.core.files
+
+import com.muwire.core.Event
+
+/**
+ * Should be triggered by the old PersisterService
+ * once it has finished reading the old file
+ *
+ * @see PersisterService
+ */
+class PersisterDoneEvent extends Event{
+}

core/src/main/groovy/com/muwire/core/files/PersisterFolderService.groovy

@@ -19,6 +19,8 @@ import java.util.logging.Level
  *
  * The absolute path's 32bit hash to the shared file is used
  * to build the directory and filename.
+ *
+ * This persister only starts working once the old persister has finished loading
  * @see PersisterFolderService#getJsonPath
  */
 @Log
@@ -46,8 +48,8 @@ class PersisterFolderService extends BasePersisterService {
         persisterExecutor.shutdown()
     }
 
-    void onUILoadedEvent(UILoadedEvent e) {
-        timer.schedule({ load() } as TimerTask, 1)
+    void onPersisterDoneEvent(PersisterDoneEvent persisterDoneEvent) {
+        load()
     }
 
     void onUIPersistFilesEvent(UIPersistFilesEvent e) {

core/src/main/groovy/com/muwire/core/files/PersisterService.groovy

@@ -60,16 +60,17 @@ class PersisterService extends BasePersisterService {
                         }
                     }
                 }
-                // TODO: should PersisterFolderService be the one doing this?
-                listener.publish(new AllFilesLoadedEvent())
+                // Backup the old hashes
+                location.renameTo(
+                        new File(location.absolutePath + ".bak")
+                )
+                listener.publish(new PersisterDoneEvent())
             } catch (IllegalArgumentException e) {
                 log.log(Level.WARNING, "couldn't load files",e)
             }
         } else {
-            // TODO: should PersisterFolderService be the one doing this?
-            listener.publish(new AllFilesLoadedEvent())
+            listener.publish(new PersisterDoneEvent())
         }
-        // TODO: Get rid of the files.json
         loaded = true
     }