indent with tabs not spaces

Found these with:
git grep "^  " $(find -type  f -name \*.hs) |grep -v ':  where'

Unfortunately there is some inline hamlet that cannot use tabs for
indentation.

Also, Assistant/WebApp/Bootstrap3.hs is a copy of a module and so I'm
leaving it as-is.

Logs/MapLog.hs

@@ -15,7 +15,7 @@ import qualified Data.Map as M
 import Data.Time.Clock.POSIX
 import Data.Time
 import System.Locale
-  
+
 import Common
 
 data TimeStamp = Unknown | Date POSIXTime