Evas Text/Textblock: Use locale for lang as default.

Evas Text/Textblock: Use locale for lang as default.

Summary:
The configuration files for Fontconfig can describe
how font list is made according to language information.
EFL also set the language for each Evas textblock styles
and used for loading font list.

But, this is inconvenient to use if we want to apply language
for loading font list according to system-wide locale information.
This patch will apply locale information for font list if there is
no specific language in description.

And it also add [lang=auto] for Evas Textblock.
auto - It loads locale for language.
none - It disables language.

@feature

Test Plan: N/A

Reviewers: woohyun, herdsman, tasn

Subscribers: jpeg, cedric

Differential Revision: https://phab.enlightenment.org/D3344

Change-Id: I7a4d3d8d7a841f6f82190695488c28db86a91486