UX for MP frontend

[chadvandy]

• improve the popup a bit (it's a lil ugly)
• change the view in the "how it works" bit to display the host's name and say "%s's Settings" with a ? explaining how it works
• some sort of explanation that settings won't be synced until the game starts and that MP support should be considered slightly finnicky; any issues, report to moi
• import/export buttons for clients/host, copy settings to clipboard and/or file, as a way to force a sync in the frontend before a new game; some apology therein that it's clunky but it's the best I can do since I can't make PCs talk to each other easily outside of campaign
• a warning about sync first-turn issues if the sync isn't done on frontend
• highlight on MCT button, w/ added tooltip for "open pls! sync stuff! it's good I swear!"
• trigger popup on MCT open instead of immediately
• set mp-disabled and similar settings