fetch-pack: perform a fetch using v2

When communicating with a v2 server, perform a fetch by requesting the
'fetch' command.

Signed-off-by: Brandon Williams <bmwill@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

fetch-pack.h

@@ -3,6 +3,7 @@
 
 #include "string-list.h"
 #include "run-command.h"
+#include "protocol.h"
 
 struct oid_array;
 
@@ -43,7 +44,8 @@ struct ref *fetch_pack(struct fetch_pack_args *args,
 		       struct ref **sought,
 		       int nr_sought,
 		       struct oid_array *shallow,
-		       char **pack_lockfile);
+		       char **pack_lockfile,
+		       enum protocol_version version);
 
 /*
  * Print an appropriate error message for each sought ref that wasn't