Summary:
fileselector_button and fileselector_entry should have almost same interfaces with fileselector.
Previously , we exposed them individually such as elm_fileselector_is_save_set().
Instead of adding the same APIs three times, we can reuse one fileselector's API using Eo interface.
This patch introduced fileselector interface and applied it to elm_fileselector.
Reviewers: seoz, raster
Reviewed By: raster
Differential Revision: https://phab.enlightenment.org/D475
Daniel Zaoui
Ryuan Choi