Makefile now builds using cabal, taking advantage of cabal's automatic detection of appropriate build flags.

The only thing lost is ./ghci

Speed: make fast used to take 20 seconds here, when rebuilding from
touching Command/Unused.hs. With cabal, it's 29 seconds.

Utility/UserInfo.hs

@@ -28,7 +28,7 @@ myUserName :: IO String
 myUserName = myVal ["USER", "LOGNAME"] userName
 
 myUserGecos :: IO String
-#ifdef WITH_ANDROID
+#ifdef __ANDROID__
 myUserGecos = return "" -- userGecos crashes on Android
 #else
 myUserGecos = myVal [] userGecos