added: column 'guest_name' to 'item' table

used when user_id is -1
added: mount parameters: thread_with_info, thread_with_header
added: function rm can remove threads



git-svn-id: svn://ttmath.org/publicrep/cmslu/trunk@506 e52654a7-88a9-db11-a3e9-0013d4bc506e

core/item.h

@@ -24,6 +24,9 @@ long user_id;
 long group_id;
 int privileges;
 
+// used as a user name when user_id is equal -1
+std::string guest_name;
+
 tm date_creation;
 tm date_modification;
 
@@ -77,6 +80,8 @@ void Clear()
 	group_id = -1;
 	privileges = 0;
 	
+	guest_name.clear();
+	
 	subject.clear();
 	content.clear();
 	url.clear();