Summary:
most usage of simple list, items are very limited and loading performance is not serious.
to support those requirement, this efl.ui.list will create scrollable box with efl.pack.
user can create list by packing an pre-loaded item object, Efl.Ui.List.Item class.
Test Plan: tested in efl_ui_list_example_1.c in examples.
Reviewers: cedric, felipealmeida
Subscribers: woohyun, Jaehyun_Cho
Differential Revision: https://phab.enlightenment.org/D5861
SangHyeon Lee