Quote the path passed to hh_server

Summary: When hh_client spawns a server, quote the path so that paths with spaces in the
name are correctly handled.

Fixes facebook#4310

Closes facebook#4321

Reviewed By: @​svcscm

Differential Revision: D1701186

Pulled By: @int3

hphp/hack/src/client/clientStart.ml

@@ -51,8 +51,8 @@ let start_server env =
         "")
     | None -> "" in
   let hh_server = Printf.sprintf "%s -d %s %s"
-    (get_hhserver())
-    (Path.string_of_path env.root)
+    (Filename.quote (get_hhserver()))
+    (Filename.quote (Path.string_of_path env.root))
     server_options in
   Printf.fprintf stderr "Server launched with the following command:\n\t%s\n%!"
     hh_server;

hphp/hack/src/utils/shell.ml

@@ -8,11 +8,6 @@
  *
  *)
 
-(** This is probably not fully safe. It'll do a reasonable job of escaping
-    silly things like spaces, quotes and so on but there are probably ways
-    to break it. *)
-let escape_string_for_shell str =
-  let escaped = Str.global_replace (Str.regexp "'") "'\"'\"'" str in
-  "'" ^ escaped ^ "'"
+let escape_string_for_shell = Filename.quote
 
 let escape_spaces str = Str.global_replace (Str.regexp " ") "\\ " str