check if fruits are actually configured to be persistent before doing persistence
when hitting a fruit with stick, do not attempt to grow it (was futile anyway, just wastes cpu)
pumpkins and melons are the only non-transparent crops, for these take the light level from one block above when getting growth rate, as otherwise it is reported as zero. This will only happen when right clicking the block with a stick.
minor code readibilty improvement in GrowListener
always set the fruit growth of a stem to zero if a fruit is found nearby