Add !gift <player> <credits> functionality

[mobeigi]

I think it would be a good idea to add !gift functionality for streamline credit gifting.

This is a pretty easy fix, I already have the solution but its for an older version of Store so it may conflict with latest store-gifting.

Once other issues are fixed, perhaps I could add this enhancement to the latest build.

[Chdata]

you could do this easily with the store_givecredits native

[mobeigi]

Yeah its easy but useful. I'm already using it.
!gift brings up menu but !gift gifts credits to a player.