spinner: spinner entry reactivate when focus come again.

spinner: spinner entry reactivate when focus come again.

Summary:
When user edit spinner value on entry.
The user want to back on entry to edit spinner value even swiching view(focus out and focus in).

I considered a couple of exception case ( case that entry should not reactivate.)
1. User click spinner button to give focus.
2. User give focus to spinner's object using key action.

Test Plan:
Add sample in elementary_test.
Edit spinner value.
Gives focus to other window.
Back to spinner view.
See the action.

Reviewers: Hermet, woohyun, cedric, jpeg

Subscribers: cedric, jpeg

Differential Revision: https://phab.enlightenment.org/D4120