Course create/update/cancel now navigates back to where u came from (namely /course/index.php & /course/category.php).
(except when creating by default in Misc whereby you're sent to Misc where the course was created)
That was becuase not enough information was being passed in for the blocks editing controls to construct the right URL to reload the page.
It is also now possible for admin external pages to add some UI next to the turn blocks editing on/off button. For example, when you are editing the list of course catgories, the turn editing off button is now in the right place.
* Note: this would never lead to problems with default role definions.
* Also ended up mostly rewriting delete_category_form to simplify the messages that are displayed.
* New helper function require_all_capabilities, a bit like require_any_capability.