* Add `clear_prefix()` to redis_cli APP, this feature need redis 2.6+ version
* Add version check to redis_cli APP, default is disabled
* Add `clear_table()` to objcache APP
* Add 'id' parameter to `get()` and `get_object()` and `get_cached_object()` functions,
  so that if the ID can't be found in cache, condition (old parameter) will be used.
  And when id and condition given both, only when id is not integer or valid expression
  condition will be used. So in most cases, you don't need pass condition.
If not set url option for session of database type, it'll automatically use ORM settings if exists