WICKET-6105 and WicketStuff

[Andrea Del Bene]

Hi,

WicketStuff is currently depending on Wicket 'wicket-datetime' for three 
subprojects:

- wicket-scala

- inmethod-grid

- wicketstuff-portlet-examples

I think we should replace it with the corresponding module we have 
migrated to WicketStuff.

What do you think?