avoid floating point desync, other script tweaks

So. A while ago, while trying to prevent hogs blowtorching getting turned around, unc0rr altered the old range of blowtorch from 1/8th of 180° up or down, to a 4° gain in upwards and a -4° loss in downwards. He also made it so that starting tunnels could fail to erase sufficient terrain, trapping hogs. Here are a couple of workarounds to more closely approximate old behaviour (do some initial erasure, adjust min/max angles)

Safety check. The main place this can be a problem is on a mild bowl w/ multiple hogs. Could possibly add a hog collision check in here.

split version information in engine too

drop useless option, automatically set revision and debug info

split cVersionString into its three separate components (version, revision, hash) and apply the new values sensibly on the frontend (esp. title, info and feedback)

mysterious merge