sameas RemoteConfig inheritance

I found a way to avoid inheritance complicating anything outside of
Logs.Remote. It seems fine to require all inherited values to be
inherited and not set in the sameas remote's config. Since inherited
values will be used for stuff like encryption and perhaps chunking, which
control the actual content stored on the remote, it seems likely that
there will not be any reason to need them to vary between two remotes
that access the same underlying data store.

The newer version of containers is free; the minimum ghc version is
bundled with a newer version than that.

Crypto.hs

@@ -45,6 +45,7 @@ import qualified Utility.Gpg as Gpg
 import Types.Crypto
 import Types.Remote
 import Types.Key
+import Annex.SpecialRemote.Config
 
 {- The beginning of a Cipher is used for MAC'ing; the remainder is used
  - as the GPG symmetric encryption passphrase when using the hybrid
@@ -236,7 +237,7 @@ instance LensGpgEncParams (RemoteConfig, RemoteGitConfig) where
 	getGpgEncParams (c,gc) = getGpgEncParamsBase (c,gc) ++
  		{- When the remote is configured to use public-key encryption,
 		 - look up the recipient keys and add them to the option list. -}
-		case M.lookup "encryption" c of
+		case M.lookup encryptionField c of
 			Just "pubkey" -> Gpg.pkEncTo $ maybe [] (splitc ',') $ M.lookup "cipherkeys" c
 			Just "sharedpubkey" -> Gpg.pkEncTo $ maybe [] (splitc ',') $ M.lookup "pubkeys" c
 			_ -> []