elementary: add a factory that handle caching for you.
This factory handle caching of one type of object and automatically empty the cache
when the application goes into pause.
Creating object is costly and time consuming, keeping a few on hands for when you next will need them help a lot.
This is what this factory caching infrastructure provide. It will create the object from the class defined on it,
set the parent and the model as needed for all items a Factory create. The View has to release the Item using the
release function of the Factory interface for all of this to work properly.
This is copying what Elm_Genlist was doing for you in the background and bring Efl interface to parity.
Reviewed-by: Felipe Magno de Almeida <email@example.com>
Differential Revision: https://phab.enlightenment.org/D7443