Use ICU transliterator for Greek uppercase and add support for Lithuanian.

Also make the locale detection code more robust. In the past, only "tr" and "az" (without any other components) are detected as Turkic. Now, "tr_TR", 'tr-TR' and 'tr@...' etc are all considered as Turkic. The same is true of Greek and Lithuanian. 

ICU transliterator is used for Greek uppercase only because other cases (Turkic and Lithuanian and Greek lowercasing) are well supported by ICU's u_strToFoo. 


BUG=304911,234797	
TEST=Layout tests(fast/text/text-transform*) and wtf_unittests:WTF.String*Locale

Review URL: https://codereview.chromium.org/108653007

git-svn-id: svn://svn.chromium.org/blink/trunk@165161 bbb929c8-8fbe-4397-9dbb-9b2b20218538