Fix email text

[gammaw]

Please change the following:

• Use "EM GUIDE" instead of "EM Guide";
• Make email subject specific (bodies are good):
  • For Article notification:
    • "EM GUIDE: XXX has created a new article: YYY"
    • "EM GUIDE: Article YYY has a new comment"
  • For TL notification:
    • "EM GUIDE: Translation request has been created for YYY by XXX"
    • "EM GUIDE: Translation request for YYY has been updated"

Rationale: Email clients display threads based on subject text and with the above the users will hopefully have a smooth display.

[gammaw]

Thanks @revnandi, just tried, looks all good!