Added Yandex & Mail.ru browsers

Added detection of:
-Yandex Browser (http://browser.yandex.com/)
-Mail.ru "Internet" Browser (http://internet.mail.ru/)
-Mail.ru Amigo Browser (http://amigo.mail.ru/)

Note that Mail.ru Amigo and Internet Browsers have the same UA-string,
so they're both detected as a generic "Mail.ru Chromium Browser".