Add mixOff function.

app/coffee/utils.coffee

@@ -31,5 +31,15 @@ bindOnce = (scope, attr, continuation) =>
         delBind() if delBind
 
 
+mixOf = (base, mixins...) ->
+    class Mixed extends base
+
+    for mixin in mixins by -1 #earlier mixins override later ones
+        for name, method of mixin::
+            Mixed::[name] = method
+    Mixed
+
+
 taiga = @.taiga
 taiga.bindOnce = bindOnce
+taiga.mixOf = mixOf