Drop Mongolian; tighten up the policy on Armenian-Latin
Mongolian is written vertically so that it's of little use in domain
Depending on fonts, a few Armenian letters can be mistaken for Latin
letters and vice-versa. Blocks mixing of Armenian and Latin.
It's in line with Amnic policy (https://www.amnic.net/policy/en/
below. It's also in line with Verisign's Armenian script policy. As a
result, this change does not affect any domain in .com as of 20170520.
.հայ domain name might contain only Latin 0-9 numbers, '-' (dash) and
Unicode Armenian letters except the letter 'և' (0587).