webapp: Progess bar fixes for many types of special remotes.

There was confusion in different parts of the progress bar code about
whether an update contained the total number of bytes transferred, or the
number of bytes transferred since the last update. One way this bug
showed up was progress bars that seemed to stick at zero for a long time.
In order to fix it comprehensively, I add a new BytesProcessed data type,
that is explicitly a total quantity of bytes, not a delta.

Note that this doesn't necessarily fix every problem with progress bars.
Particularly, buffering can now cause progress bars to seem to run ahead
of transfers, reaching 100% when data is still being uploaded.

Types/Meters.hs

@@ -1,12 +0,0 @@
-{- git-annex meter types
- -
- - Copyright 2012 Joey Hess <joey@kitenet.net>
- -
- - Licensed under the GNU GPL version 3 or higher.
- -}
-
-module Types.Meters where
-
-{- An action that can be run repeatedly, feeding it the number of
- - bytes sent or retrieved so far. -}
-type MeterUpdate = (Integer -> IO ())

Types/Remote.hs

@@ -15,9 +15,9 @@ import Data.Ord
 import qualified Git
 import Types.Key
 import Types.UUID
-import Types.Meters
 import Types.GitConfig
 import Config.Cost
+import Utility.Metered
 
 type RemoteConfigKey = String
 type RemoteConfig = M.Map RemoteConfigKey String