Add SysTray notification for DB backup. More translations.

Added a setting "showBackupNotification", which is false by default,
that shows a tray notification when a repository backup occurs.

Above notification, and the auto-update notification, now refer to
the SysTray i18n translation lookup resources.

src/main/resources/i18n/SysTray_en.properties

@@ -1,6 +1,10 @@
 #Generated by ResourceBundle Editor (http://essiembre.github.io/eclipse-rbe/)
 # SysTray pop-up menu
 
+APPLYING_UPDATE_AND_RESTARTING = Applying automatic update and restarting...
+
+AUTO_UPDATE = Auto Update
+
 BLOCK_HEIGHT = height
 
 CHECK_TIME_ACCURACY = Check time accuracy
@@ -9,6 +13,10 @@ CONNECTION = connection
 
 CONNECTIONS = connections
 
+CREATING_BACKUP_OF_DB_FILES = Creating backup of database files...
+
+DB_BACKUP = Database Backup
+
 EXIT = Exit
 
 MINTING_DISABLED = NOT minting