New player mode features

[NBKelly]

Slowly cracking through this.

Right now:

• Commands to disable/enable playing with open info
• Installed facedowns are visible on mouse-over via card preview (maybe they could flip faceup on mouseover? that's a problem for somebody else)

TODOS (only related to what I've done):

• In new player mode, there should be a dedicated button for this command. I think I'll actually copy the playtester panel lostgeek did years ago for this stuff.

Just checking for title on if a card can be moused over could potentially reveal any leaks we have on diffs as well.