first pass at alert buttons

They work fine. But I had to go to a lot of trouble to get Yesod to render
routes in a pure function. It may instead make more sense to have each
alert have an assocated IO action, and a single route that runs the IO
action of a given alert id. I just wish I'd realized that before the past
several hours of struggling with something Yesod really doesn't want to
allow.

Command/WebApp.hs

@@ -16,6 +16,7 @@ import Assistant.ScanRemotes
 import Assistant.TransferQueue
 import Assistant.TransferSlots
 import Assistant.Threads.WebApp
+import Assistant.WebApp
 import Utility.WebApp
 import Utility.Daemon (checkDaemon, lockPidFile)
 import Init
@@ -92,10 +93,12 @@ firstRun = do
 	scanremotes <- newScanRemoteMap
 	transferqueue <- newTransferQueue
 	transferslots <- newTransferSlots
+	urlrenderer <- newUrlRenderer
 	v <- newEmptyMVar
 	let callback a = Just $ a v
 	void $ runNamedThread dstatus $
-		webAppThread Nothing dstatus scanremotes transferqueue transferslots
+		webAppThread Nothing dstatus scanremotes
+			transferqueue transferslots urlrenderer
 			(callback signaler) (callback mainthread)
 	where
 		signaler v = do