elua: allow setting of default domain

src/bindings/luajit/eina/log.lua

@@ -189,6 +189,8 @@ M.Domain = M.Domain_Base:clone {
     end
 }
 
-M.set_default_domain = f
+M.set_default_domain = function(dom)
+    default_domain = dom:__get_domain()
+end
 
 return M

src/examples/elua/elm_test.lua

@@ -11,10 +11,12 @@ log.log_err("test with default log domain")
 
 local foo = function()
     for i = 1, 4 do
-        dom:log(log.level.ERR, "testing: " .. i)
+        log.log_err("testing: " .. i)
     end
 end
 
+foo()
+log.set_default_domain(dom)
 foo()
 
 win:smart_callback_add("delete,request", function()