Cosmetic
Improved class instance with static
Improved SELECT control with first item option
Improved copy & paste
Fixed null value and improves image size registration with label
* Added `WPDKUser::getTransientWithUser()`
* Added `WPDKUser::getTransient()`
* Deprecated `wpdk_get_user_transient()` use WPDKUser::getTransientWithUser()` instead
* Added `WPDKUser::getTransientTimeWithUser()`
* Added `WPDKUser::getTransientTime()`
Merge Master