* Router: Refactor periodic tasks to their own files

apps/routerconsole/java/bundle-messages.sh

router/java/src/net/i2p/router/Router.java

router/java/src/net/i2p/router/tasks/CoalesceStatsEvent.java

router/java/src/net/i2p/router/tasks/MarkLiveliness.java

...r/java/src/net/i2p/router/tasks/PersistRouterInfoJob.java

router/java/src/net/i2p/router/tasks/Republish.java

router/java/src/net/i2p/router/tasks/RouterWatchdog.java

router/java/src/net/i2p/router/tasks/ShutdownHook.java

router/java/src/net/i2p/router/tasks/Spinner.java

...src/net/i2p/router/tasks/UpdateRoutingKeyModifierJob.java

router/java/src/net/i2p/router/tasks/package.html