ATM, DRE, MFT support, one KA-engine tweak.

Not much interesting here, honestly:

* ATM support
* DRE support, all pretty straightforward - everything is either a dead structural part/fuel tank (1450-1500c) or an engine (1800c, adjust heat generation).
* MFT tank types have Karborundum added
* Small tweak to the tiny KA engine, slightly more efficient in vacuum, less efficient @ SL. There's no hard&fast rule here, so feel free to narrow the gap some to taste but even the aerospike has *some* difference.