Sneak glitch: Set default to false

Sneak glitch: Set default to false

The 'sneak glitch' physics override now controls whether a player can
use the new move code replications of the old sneak side-effects:
sneak ladders and 2 node sneak jump. This completes our intention to
replicate the old sneak side-effects in new code and provide them as
an option that is disabled by default.