Issue #1137416 by DaleIT: "No blocks" functionality can cause issues if a region is just named "sidebar"

Issue #1123546 by zenlan: New nodes created with the node_add page manager task would have invalid language.

Issue #1103278 by dereine: Add CRUD function to enable/disable objects. Update the api version to make it easy for modules to detect the presence of the new function.

Issue #1102252: Implement and document default object caching, taken mostly from how Views used to do it.

Kris Vanderwater authored Apr 07, 2011 and Earl Miles committed Apr 21, 2011

removing the logic for not building menu items for "none" parents. page_manager should never be creating a default local task for a menu item that it is not also in control of or taking over #1119782

Issue #1105624 by ygerasimov: Using wrong variable to record files needed for form loading in node add/edit context.

Issue #117072 by danielnolde: Correct reading of status so that users without "administer nodes" permissions do not get erroneous errors about not being able to add nodes.

Handle the occasion when an existing module adds "export" capability to schema and export_ui asks for it for the first time, force the schema to reset.