Add the new utils plugin, change entity spawning and the lookup command plugins to use it.

data/plugins/util/intercept.rb

@@ -0,0 +1,27 @@
+# Essentially a wrapper for specific message types to make them easier to use. Only supports the interception of a message type once (for good reason - this is supposed to
+# be a utility, not a chain of interceptors inside the existing chain).
+#
+# Plugins that wish to expand the list of available message types (you probably don't) should use the add_interception method - see the item-on-item script for example usage.
+# 
+# If you only wish to intercept a message, use the intercept method, e.g.
+#
+# intercept :item_on_item, used_id, target_id, :irreversible do |ctx, player, message|
+#   # code here
+# end
+
+
+# Calls the registered interception(s), if applicable.
+def intercept(message, *args, &block)
+  raise 'Error - interceptions must provide a block.' unless block_given?
+  interception = INTERCEPTIONS[message]
+
+  if interception == nil then raise "No interception for message #{message}" else interception.call(*args, block) end
+end
+
+# Adds an interception.
+def add_interception(message, &block)
+  INTERCEPTIONS[message] = block
+end
+
+private
+INTERCEPTIONS = {}