Make CraftMinecartHopper work as InventoryHolder. Adds BUKKIT-3796
Implement InventoryPickupItemEvent. Adds BUKKIT-3798
Implement new cause versions of BlockIgniteEvent. Addresses BUKKIT-3609, BUKKIT-3656, BUKKIT-3657

Conflicts:
	src/main/java/org/bukkit/craftbukkit/event/CraftEventFactory.java
Implement per-player Weather API. Adds BUKKIT-812
Only set player weather if a plugin requested it.

If the server changes the weather it will set the per-player weather
variable and future changes will not apply. We should only set this
variable when a plugin is requesting per-player weather and not when
the server it doing it.
Add /testfor command support to command block. Adds BUKKIT-3813
Only filter data on block items, not all items.