Improve error handling

* remove some obsolete functions and error types from HPath.IO.Errors
  that are completely unused
* reworked the RecursiveFailure type to contain more information,
  so we can use it to programmatically make useful choices
  without examining the weakly types IO error attributes (like
  'ioGetFileName')

test/HPath/IO/MoveFileSpec.hs

@@ -112,14 +112,14 @@ spec = beforeAll_ (upTmpDir >> setupFiles) $ afterAll_ cleanupFiles $
                 "alreadyExists"
                 Strict
         `shouldThrow`
-        isFileDoesExist
+        (\e -> ioeGetErrorType e == AlreadyExists)
 
     it "moveFile (Strict), move from file to dir" $
       moveFile' "myFile"
                 "alreadyExistsD"
                 Strict
         `shouldThrow`
-        isDirDoesExist
+        (\e -> ioeGetErrorType e == AlreadyExists)
 
     it "moveFile (Strict), source and dest are same file" $
       moveFile' "myFile"