embed test suite into git annex; available by running: git annex test

I have seen some other programs do this, and think it's pretty cool. Means
you can test wherever it's deployed, as well as at build time.

My other reason for doing it is less happy. Cabal's handling of test suites
sucks, requiring duplicated info, and even when that's done, it fails to
preprocess hsc files here. Building it in avoids that and avoids having
to explicitly tell cabal to enable test suites, which would then make it
link the test executable every time, which is unnecessarily slow.

This also has the benefit that now "make fast test" does a max speed build
and tests it.

Command/Test.hs

@@ -0,0 +1,33 @@
+{- git-annex command
+ -
+ - Copyright 2013 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Command.Test where
+
+import Common.Annex
+import Command
+import qualified Command.Init
+import qualified Command.Add
+import qualified Command.Drop
+import qualified Command.Get
+import qualified Command.Move
+import qualified Command.Copy
+import qualified Command.Sync
+import qualified Command.Whereis
+import qualified Command.Fsck
+import qualified Test
+
+def :: [Command]
+def = [noCommit $ noRepo showHelp $ dontCheck repoExists $
+	command "test" paramNothing seek "run built-in test suite"]
+
+seek :: [CommandSeek]
+seek = [withWords start]
+
+start :: [String] -> CommandStart
+start _ = do
+	liftIO $ Test.main
+	stop