This considerably reduces frequency of repathing attempts without too much of an impact of in-game repathing speed, since most of the time the blocking actor doesn't move out of the way that fast anyway.
Add GrantConditionOn*Layer traits
This allows to
- drop some booleans from Locomotor
- drop a good part of the subterranean- and jumpjet-specific code/hacks from Mobile
- grant more than 1 condition per layer type (via multiple traits)
- easily add more traits of this kind for other layers
