Thar be bc breaks here!

* The renderPage method added to your module by the asset mixin is much improved, it does everything the pages module used to do when rendering a "regular page" from the page tree. In fact, the pages module now depends on it.
* Arguments to the asset mixin's renderPage method have changed. It is now req, template, data, and occasionally "when". The req object can automatically supply when if you don't need to override that.
* Responsibility for rendering full HTML page responses has moved from the pages module to the core apostrophe module. The pages module really should be responsible only for tree pages and the management of page types.
* prunePage is now a method of the apos object, not the pages object.