evas: Evas_Box - layout_flow_horizontal and layout_flow_vertical fix

evas: Evas_Box - layout_flow_horizontal and layout_flow_vertical fix

Summary:
Now minimum width hint (for horizontal layout) and minimum height hint (for vertical)
are set to largest item size rather than largest row/column.

@fix

Test Plan:
1. Run "elementary_test"
2. Maximize window
3. Unmaximize it
ExR: button boxes should return to start state.

Reviewers: cedric, seoz, Hermet

Subscribers: cedric, reutskiy.v.v

Differential Revision: https://phab.enlightenment.org/D1511

Signed-off-by: Cedric BAIL <cedric@osg.samsung.com>