Fixing form data binding for lists having more than 256 elements

Spring data binding enforces a limit of 256 elements for auto-growing collections (see DEFAULT_AUTO_GROW_COLLECTION_LIMIT in https://github.com/spring-projects/spring-framework/blob/master/spring-context/src/main/java/org/springframework/validation/DataBinder.java).

This imposes a restriction of 256 elements as a maximum for Play form collections binding. This limit can be removed by setting the maximum value to Integer.MAX_VALUE (which is also the default in https://github.com/spring-projects/spring-framework/blob/master/spring-context/src/main/java/org/springframework/validation/BeanPropertyBindingResult.java... it looks like Spring has inconsistent default values for their collection binding).