[WICKET 7] Signature of RefreshingView constructor

[Martijn Dashorst]

I'm working through our internal framework upgrading Wicket to 7. This
is one place I think the Wicket API can improve further:

Currently the constructor of RefreshingView is defined as:

    public RefreshingView(String id, IModel<? extends Collection<?
extends T>> model)

Probably the model can be better typed with IModel<? extends
Iterable<? extends T>>

WDYT?

Martijn