Adding ability for hooks to return, and OnRaw hook

By adding the ability for hooks to return, we can stop the processing of a line at any point.
This is used by the OnRaw hook such that any non-nil return value will cause the irc library to assume that line has been handled.

init.lua

@@ -163,7 +163,10 @@ end
 function meta:think()
 	while true do
 		local line = getline(self, 3)
-		if line then
			self:handle(parse(line))
+		if line then
+			if not self:invoke("OnRaw", line) then
+				self:handle(parse(line))
+			end
 		else
 			break
 		end
@@ -292,7 +295,7 @@ end
 function meta:handle(prefix, cmd, params)
 	local handler = handlers[cmd]
 	if handler then
-			handler(self, prefix, unpack(params))
+		return handler(self, prefix, unpack(params))
 	end
 end