Logging: Free by finalize is a leak

Conflicts:
	src/freenet/support/io/TempBucketFactory.java
Fix bucket leak
Fix a bucket leak in updater code
Fix leak in SlashdotStore and add logging
Fix bucket leak in inserting date hints

Conflicts:
	src/freenet/client/async/USKInserter.java
Fix concurrency issue resultin in IMPOSSIBLE: BUCKET IS NULL and bucket leaks
Delete unused methods re last data fetched
lastRequestData is now only used internally, so we need to free it.

Conflicts:
	src/freenet/client/async/USKFetcher.java
Consistently synchronize when accessing lastRequestData
Start the plugins off-thread. Don't let them block the rest of startup. If they are loaded from Freenet, they could take a long time to load, especially if they also block IP detection!
Merge remote-tracking branch 'toad/leak-fixes' into next
Merge remote-tracking branch 'toad/start-plugins-off-thread' into next