add version information to InferAnalyze output

Summary:
@public
This changes "Starting analysis" into
"Starting analysis (Infer version XXX)".

Test Plan:
  infer -- clang -c hello.c

shows "Starting analysis (Infer version git-6b9fb8838bcabd2af881554d296963a849b14f50)"

infer/src/backend/inferanalyze.ml

@@ -731,7 +731,7 @@ let analyzer_err_name = "analyzer_err"
 let () =
   let () =
     match !cluster_cmdline with
-    | None -> L.stdout "Starting analysis@.";
+    | None -> L.stdout "Starting analysis (Infer version %s)@." Version.versionString;
     | Some clname -> L.stdout "Cluster %s@." clname in
   RegisterCheckers.register ();
   Facebook.register_checkers ();