fix --from overriding annex-ignore

Make git-annex get/copy/move --from foo override configuration of
remote.foo.annex-ignore, as documented.

This already worked for remotes supporting hasKeyCheap. For others though,
git-annex copy --from foo would silently not do anything, while
git-annex copy --to foo would use the annex-ignored remote.

Also improved the annex-ignore docs, to reflect that `git-annex get`
without --from will skip using annex-ignored remotes, for example.

Sponsored-by: Dartmouth College's DANDI project

Assistant/TransferQueue.hs

@@ -93,7 +93,7 @@ queueTransfersMatching matching reason schedule k f direction
 				filter (\r -> not (inset s r || Remote.readonly r))
 					(syncDataRemotes st)
 	  where
-		locs = S.fromList . map Remote.uuid <$> Remote.keyPossibilities k
+		locs = S.fromList . map Remote.uuid <$> Remote.keyPossibilities (Remote.IncludeIgnored False) k
 		inset s r = S.member (Remote.uuid r) s
 	gentransfer r = Transfer
 		{ transferDirection = direction