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