Added boolean settings for plugins

src/plugins/themes.h

@@ -32,6 +32,11 @@
  *
  */
 
+#ifndef PLUGIN_THEMES_H
+#define PLUGIN_THEMES_H
+
 void plugin_themes_init(void);
 void plugin_themes_close(void);
 theme_item_t plugin_themes_get(const char *const group, const char *const key, const char *const def);
+
+#endif