ecs: add callbackFiltered and emitFiltered

ecs/timer.can

@@ -1,35 +0,0 @@
---- Timer system
--- Handles ubiquitousse timers.
-
-let timer = require((...):match("^(.-)ecs%.timer").."scene")
-
-return {
-	name = "timer",
-	filter = "timer",
-	default = {
-		-- timer object
-	},
-	process = :(t, dt)
-		t:update(dt)
-		if t:dead() then
-			@world:remove(t.entity)
-		end
-	end,
-	--- System methods ---
-	--- Add a new timer
-	run = :(func)
-		local t = timer.run(func)
-		@world:add {
-			timer = t
-		}
-		return t
-	end,
-	--- Add a new tween
-	tween = :(duration, tbl, to, method)
-		local t = timer.tween(duration, tbl, to, method)
-		@world:add {
-			timer = t
-		}
-		return t
-	end
-}