Predator round awareness

[Sarah_U.]

Summary (a quick, 2-3 sentence summary):
Add a message inside the lobby if the game's a predator round for new joiners and start lobbiers.

Benefits (How this will benefit the server and game as a whole):
It'll increase predator round awareness and grant people with whitelist opportunities to flag up before they join marine or xeno.

Details (Description of how you think this would work, the benefits, etc):
Round starts: During the process as far as I know the predator round is flagged on or off; If the round is on, a message will be displayed after people are inside the game to show that it's a predator round (Only visible to non-players).
Player joins later-on: He's greeted with a pred round in progress message.

Implementation (Optional, if you have an idea how to implement it):
[N/A]

[forwardslashN]

Predator rounds are determined after the round has started. This isn't possible right now. Edit: Though I may do this if I ever rewrite the way we handle game modes in the future. Resolved for now.