Änderungen

fix ClosureForGroups.forNearestDestructable() (#290)
* fix ClosureForGroups.forNearestDestructable()
 Previous version was not working it all. It was using
filterEnumDestructablesInCircleBJ, which uses some bj vars and requires
them to be set, which were not. It could be fixed with just setting this
variables, but previous implementation has some other issues: distance
was calculated two times (in the filter function and in the enum
function) and the rect created was not removed! Now a global rect is
reused, and the in-rect-check was moved to enum function to avoid
recalculating distance.

* Create test.j

* delete trash

* destroy callback