pulled html5 locales May 23, 2019; added Vietnamese

bigbluebutton-html5/imports/startup/client/intl.jsx

bigbluebutton-html5/private/locales/bg_BG.json

bigbluebutton-html5/private/locales/cs_CZ.json

bigbluebutton-html5/private/locales/de.json

bigbluebutton-html5/private/locales/el_GR.json

bigbluebutton-html5/private/locales/es.json

bigbluebutton-html5/private/locales/es_ES.json

bigbluebutton-html5/private/locales/es_MX.json

bigbluebutton-html5/private/locales/eu.json

bigbluebutton-html5/private/locales/fa_IR.json

bigbluebutton-html5/private/locales/fr.json

bigbluebutton-html5/private/locales/hi_IN.json

bigbluebutton-html5/private/locales/id.json

bigbluebutton-html5/private/locales/it_IT.json

bigbluebutton-html5/private/locales/ja.json

bigbluebutton-html5/private/locales/ja_JP.json

bigbluebutton-html5/private/locales/km.json

bigbluebutton-html5/private/locales/pl_PL.json

bigbluebutton-html5/private/locales/pt.json

bigbluebutton-html5/private/locales/pt_BR.json