The /butcher command no longer kills mobs with a name tag.

This behaviour can be overridden with the new -t flag.
The -f flag encompasses this flag.
The /butcher command no longer kills mobs with a name tag.

PR: https://github.com/sk89q/worldedit/pull/292

Conflicts:
	src/bukkit/java/com/sk89q/worldedit/bukkit/BukkitWorld.java
	src/main/java/com/sk89q/worldedit/command/BrushCommands.java
	src/main/java/com/sk89q/worldedit/command/UtilityCommands.java