webapp: Now always logs to .git/annex/daemon.log

It used to not log to daemon.log when a repository was first created, and
when starting the webapp. Now both do. Redirecting stdout and stderr to the
log is tricky when starting the webapp, because the web browser may want to
communicate with the user. (Either a console web browser, or web.browser = echo)
This is handled by restoring the original fds when running the browser.

Assistant/Threads/Watcher.hs

@@ -97,6 +97,7 @@ startupScan scanner = do
 		void $ liftIO $ cleanup
 		
 		liftAnnex $ showAction "started"
+		liftIO $ putStrLn ""
 		
 		modifyDaemonStatus_ $ \s -> s { scanComplete = True }