Allow custom broadcasts on aspects.

[pyrrhicPachyderm]

No description provided.

[iakona]

I'm assuming you have some aspects in mind that would benefit from this? I'm guessing deeps might have one about how to use the overlay tiles?

[pyrrhicPachyderm]

We've got one on Mentor at the moment (just reminding people that they can right-click "Pick Power" to gain multiple). I've just been rewriting Mentor to use the card gain hook, and the broadcast is the only thing left in its doSetup() function, so I figured with this I could just ditch its doSetup() function entirely. But that was just the original motivation; I'm sure Deeps would also greatly benefit from a broadcast.