make find show files meeting limits, even when not present

find: Rather than only showing files whose contents are present, when used
with --exclude --copies or --in, displays all files that match the
specified conditions.

Note that this is a behavior change for find --exclude! Old behavior
can be gotten with find --in . --exclude=...

Limit.hs

@@ -10,6 +10,7 @@ module Limit where
 import Text.Regex.PCRE.Light.Char8
 import System.Path.WildMatch
 import Control.Monad (filterM)
+import Control.Applicative
 import Data.Maybe
 
 import Annex
@@ -27,6 +28,10 @@ filterFiles l = do
 	matcher <- getMatcher
 	filterM (Utility.Matcher.matchM matcher) l
 
+{- Checks if there are user-specified limits. -}
+limited :: Annex Bool
+limited = (not . Utility.Matcher.matchesAny) <$> getMatcher
+
 {- Gets a matcher for the user-specified limits. The matcher is cached for
  - speed; once it's obtained the user-specified limits can't change. -}
 getMatcher :: Annex (Utility.Matcher.Matcher (FilePath -> Annex Bool))