User variable

Module for working with variables.
Analog built-in functions Drupal varible_set() / variable_get(), but with differences:
1. variables are stored in a separate table and are loaded only when necessary (which does not load the memory);
2. variables may belong to specific users;
3. variables may be dependent on the session;
4. variables can be temporary (delete by Cron);
5. variables can be global.