gfse: initial support for grammars in the cloud

This lets the user access the same set of grammars from multiple devices.

Sharing grammars between multiple users is possible but discouraged at the
moment. There is no version handling, so concurrent editing of the same grammar
by different users might result in one user overwriting changes made by
another user. (The same goes for cuncurrent editing on multiple devices by
a single user, of course.)

src/editor/simple/save.hs

@@ -1,12 +1,17 @@
-import Monad(zipWithM_)
+import Monad(zipWithM)
 import System(getArgs)
 
 main = save =<< getArgs
 
 save [dir] =
   do fs@[ns,_] <- readIO =<< getContents
-     save_all fs
-     putStrLn $ unwords [n++".gf"|n<-ns]
+     nes <- save_all fs
+     putStrLn $ unwords nes
   where
-    save_all [ns,cs] = zipWithM_ write1 ns cs
-    write1 n = writeFile (dir++"/"++n++".gf")
+    save_all [ns,cs] = zipWithM write1 ns cs
+    write1 n c = 
+       do writeFile (dir++"/"++ne) c
+          return ne
+      where
+        ne=if '.' `elem` n then n else n++".gf"
+