i just factored out component usecheck related logic out of the Page and into RequestCycle/DebugHelper. we are going to need a few more variables/methods for more checks soon and i figured page is not the best place to keep data like that.
while looking at the component usecheck though i noticed we call component begin/end render from a lot of different places. page has startcomponentrender/endcomponentrender, then renderPage() also calls those methods directly, etc. is there any reason why we couldnt just wire this into Component.onbefore/afterRender() methods we have (we will be enforcing the call to super in those via a similar check). this will mean we could remove some of our infamouse public final with the DO NOT USE THIS javadoc :) -igor
