DatabasePlugin: add attribute "flags"

src/db/DatabasePlugin.hxx

@@ -35,6 +35,8 @@ class Database;
 struct DatabasePlugin {
 	const char *name;
 
+	unsigned flags;
+
 	/**
 	 * Allocates and configures a database.
 	 */

src/db/plugins/ProxyDatabasePlugin.cxx

@@ -780,5 +780,6 @@ ProxyDatabase::GetStats(const DatabaseSelection &selection,
 
 const DatabasePlugin proxy_db_plugin = {
 	"proxy",
+	0,
 	ProxyDatabase::Create,
 };

src/db/plugins/SimpleDatabasePlugin.cxx

@@ -337,5 +337,6 @@ SimpleDatabase::Save(Error &error)
 
 const DatabasePlugin simple_db_plugin = {
 	"simple",
+	0,
 	SimpleDatabase::Create,
 };

src/db/plugins/UpnpDatabasePlugin.cxx

@@ -776,5 +776,6 @@ UpnpDatabase::GetStats(const DatabaseSelection &,
 
 const DatabasePlugin upnp_db_plugin = {
 	"upnp",
+	0,
 	UpnpDatabase::Create,
 };