Reconcile consul's address configuration section.

There were conflicting directives previously, both consul.addr and
consul.address were required to achieve the desired behavior.  The
documentation said `consul.address` was the canonical name for the
parameter, so consolidate configuration parameters to `consul.address`.

command/agent/config_parse.go

@@ -598,7 +598,7 @@ func parseConsulConfig(result **config.ConsulConfig, list *ast.ObjectList) error
 
 	// Check for invalid keys
 	valid := []string{
-		"addr",
+		"address",
 		"auth",
 		"auto_register",
 		"ca_file",