Context Navigation

Changes between Initial Version and Version 1 of Ticket #43954, comment 13

initial	v1
6	6	The above seems to work well with one caveat: the menu is ready before the `admin_init` action fires, so we can't check for changes then. Added a workaround that caches the check (in an option) and updates that cache on `admin_init` priority 100 (this means the bubbles will show up or disappear one page load later).
7	7
	8	43954.2.diff also takes care of #43953 as it removes the change check on new install or after updating WP from an older version (the pointer will show in both cases anyway).