Improved ablators, i.e. "Deadly Re-Entry Lite".

Make heat shields with zero remaining ablator fail, like in Deadly Re-Entry,
but without any of the sophisticated support for part damage, kerbal injury,
etc.

Also allows heat shields to fail under extreme thermal stress even when not
depleted.

Tweaks the inflatible heat shield so it's only really safe for grazing/lifting
re-entries, you can't just slam into the atmosphere with it.

The DLL uses code from Deadly Reentry, so the module as a whole is CC-BY-SA.
See https://github.com/ringerc/KSP-DRE-Lite .
