Rework EntityExplodeEvent. Fixes BUKKIT-4140. Adds BUKKIT-4141
Send block updates even when applyPhysics is false.  Fixes Bukkit-3971
The CraftBlock class is setting bit 0x4 of the update flag when bit 0x2
should in fact be set here.  Bit 0x2 means "do updates"; bit 0x4 means
"don't do updates if the world is static, even when bit 0x2 is set"