Mining changes + mini reworks

[Mouse]

On the mining magnet, there's a button that says "scan" or something along those lines.  If you press it, it will helpfully mark every single interesting thing on the current asteroid - a purple circle indicates a buried object of some sort, a blue dot indicates a gem, some other markings indicate tougher or weaker rocks which can be completely ignored if you're mining with a copper pick as Armok intended, and a red exclamation point indicates a rock that is explosive or full of rads.  Then, and this is a neat trick, you don't mine any tiles with a red exclamation point.  Do this, and you will never explode.

You can get the same overlay, albeit in a smaller area, by using the mining scanner inhand if you're mining in the trench or the asteroid field.