stop firing pressure plate EntityInteractEvent for ignored entities (fixes #4962)

[Trigary]

This only affects bats at the moment.

You can't see it in the patch, but the value of Entity#isIgnoreBlockTrigger() is checked after the events have been fired.

Basically, this is how stuff worked before and after Bukkit events were added to the method:

for each entity:
//Added by Bukkit: fire PlayerInteractEvent or EntityInteractEvent
//Added by Bukkit: if event not cancelled
if not isIgnoreBlockTrigger
return full power

Fixes #4962