upgrade alerts

The webapp will check twice a day, when the network is connected, to see if
it can download a distributon upgrade file. If a newer version is found,
display an upgrade alert.

This will need the autobuilders to set UPGRADE_LOCATION to the url
it can be downloaded from when building git-annex. Only builds with that
set need automatic upgrade alerts.

Currently, the upgrade page just requests the user manually download
and upgrade it. But, all the info is provided to do automated upgrades
in the future.

Note that urls used will need to all be https.

This commit was sponsored by Dirk Kraft.

Assistant/Types/Alert.hs

@@ -31,6 +31,7 @@ data AlertName
 	| CloudRepoNeededAlert
 	| SyncAlert
 	| NotFsckedAlert
+	| UpgradeAlert
 	deriving (Eq)
 
 {- The first alert is the new alert, the second is an old alert.
@@ -52,7 +53,7 @@ data Alert = Alert
 	, alertButton :: Maybe AlertButton
 	}
 
-data AlertIcon = ActivityIcon | SyncIcon | SuccessIcon | ErrorIcon | InfoIcon | TheCloud
+data AlertIcon = ActivityIcon | SyncIcon | SuccessIcon | ErrorIcon | InfoIcon | UpgradeIcon | TheCloud
 
 type AlertMap = M.Map AlertId Alert
 

Assistant/Types/DaemonStatus.hs

@@ -67,6 +67,8 @@ data DaemonStatus = DaemonStatus
 	, scheduleLogNotifier :: NotificationBroadcaster
 	-- Broadcasts a notification once the startup sanity check has run.
 	, startupSanityCheckNotifier :: NotificationBroadcaster
+	-- Broadcasts notifications when the network is connected
+	, networkConnectedNotifier :: NotificationBroadcaster
 	-- When the XMPP client is connected, this will contain the XMPP
 	-- address.
 	, xmppClientID :: Maybe ClientID
@@ -103,5 +105,6 @@ newDaemonStatus = DaemonStatus
 	<*> newNotificationBroadcaster
 	<*> newNotificationBroadcaster
 	<*> newNotificationBroadcaster
+	<*> newNotificationBroadcaster
 	<*> pure Nothing
 	<*> pure M.empty