Add postmaster/postgres undocumented -b option for binary upgrades.

This option turns off autovacuum, prevents non-super-user connections,
and enables oid setting hooks in the backend.  The code continues to use
the old autoavacuum disable settings for servers with earlier catalog
versions.

This includes a catalog version bump to identify servers that support
the -b option.

src/backend/utils/init/globals.c

@@ -85,6 +85,7 @@ pid_t		PostmasterPid = 0;
  */
 bool		IsPostmasterEnvironment = false;
 bool		IsUnderPostmaster = false;
+bool		IsBinaryUpgrade = false;
 
 bool		ExitOnAnyError = false;