Update restbuck client, create and read an order.

Update JSON converter, the id is not important, applied the DRY principle.
Update the ORDER_HANDLER to use the meta_string_variable instead of meta_variable from req.
Fix, the key in meta_variable_table, use c.key instead of c.item

library/server/wsf/src/wsf_request.e

@@ -33,7 +33,7 @@ feature {NONE} -- Initialization
 				across
 					l_vars as c
 				loop
-					meta_variables_table.force (new_string_value (c.key, c.item), c.item)
+					meta_variables_table.force (new_string_value (c.key, c.item), c.key)
 				end
 			else
 				create meta_variables_table.make (0)