Changed all player to AGM_Core_fnc_player.

Added altimeter, shows height ASL. Decent rate (which I'm sure I am doing wrong :D). And time.
I'm guessing it would be 100% better to have an altimeter item that needs to be an assignedItem. Will cover that next.

https://github.com/KoffeinFlummi/AGM/issues/540
Hmm, with the previous method I was getting numbers in the range of 0-14. Now it's > 2000. Which I suppose is accurate for m/min but just horrible to look at.