WICKET-5545 Cannot use redirect in ModalWindow's page#onInitialize()

Just touch the modalwindow's page. There is no need to fully initialize it.

(cherry picked from commit 44cd10e85ff0145898d89bd0ee5ff19c8d32c030)
no need static methods to be final

Intellij IDEA inspections
no need private methods to be final

IDEA inspections
Update Spring to 4.0.3
Minor improvements in Wicket's HTML