Compat with TheUnderground mod.

This mod adds a new world - need to load after this guy to detect the
world(s) it generates.
Fix: Milking cows requires only /ct, not /trust.

Oddly, BOTH the block bucket event and the animal interact event fire,
and cancelling the block event also cancels the animal event.  Added a
workaround.
Added claim abandon block return ratio option.

The portion of claim blocks a player gets back when he abandons a land
claim.  These come out of his accrued blocks, not his bonus blocks.
Does not apply to administratively removed claims.  Defaults to 100%.
Fix: /gpreload now actually works.

Look at that typo!  It accidentally matched an inherited method!  Ha.
:)
Version to 8.9