* Event handlers always handle subclass events. public static $handlerList no longer required.
* Removed $handlerList declarations
* HandlerList cleanup: Removed HandlerList->handlers and related bake methods
* Removed obsolete Event->getHandlers()
* EventPriority: Added fromString()
* PluginManager: throw exceptions on registering handlers with invalid priorities
This allows specifying a handler of `EntityDamageEvent` which will handle any instanceof it (as per current behaviour), AND also now allows specifying a handler specifically for `EntityDamageByEntityEvent`, which only handles `EntityDamageEvent`.
This was not previously possible due to limitations in the way handlers were registered.
Abstract events may not be handled unless they declare the `@allowHandle` PhpDoc tag.
This now removes the need for recursing around for structures comprised of multiple blocks. Instead, override getAffectedBlocks() to return all blocks that need to be deleted when the current block is deleted, and make sure that only one half of the block drops something. When a player breaks one of the blocks, all the blocks affected by that block will also be destroyed, creating particles and sounds where appropriate.
This fixes creative drops for double plants and beds.
