Evas: Add API to reinit the language and use it in elementary.

Evas: Add API to reinit the language and use it in elementary.

Summary:
evas_common_language_from_locale_* functions kept static pointers
inside of its functions. Once these function was called, it was never reset.
It made big problems for harfbuzz and hyphenation. Also, Elementary
provides elm_language_set() API. Then we need to support it fully.
@fix

Test Plan: Test case for hyphenation is included in Evas test suite.

Reviewers: raster, tasn, herdsman, woohyun, z-wony, Blackmole, minudf

Subscribers: cedric, jpeg

Differential Revision: https://phab.enlightenment.org/D3864

Conflicts:
	src/lib/elementary/elm_main.c

The change for elementary will be applied at elementary git.

Change-Id: I747fc027973538c2d04180c23dce4c19c307419d