Set proper position of snow block. Fixes BUKKIT-5004

Missed diffs when updating to 1.7.

Pulled from PR #1278
Added EntityItemFrame.java for diff visibility
Call EntityDamageEvent on ItemFrame item removal. Fixes BUKKIT-5020

Calling this event allows plugins to react to the situation by simply
handling a normal damage event, possibly using existing code to
handle other entity damage.

Pulled from PR #1279
Call BlockPlaceEvent for cocoa beans planted on log. Adds BUKKIT-5039

The behavior of cocoa are now aligned to be the same as other plants.

Pulled from PR #1281