MDL-39454 Accesslib: is_siteadmin is a bit slow
MDL-39472 MUC: Optimise cache::get_from_persist_cache
MDL-39667 repository: Correct check for uniqueness of the name
MDL-39412 question behaviours: hide manual graded option

The ability to set all your quiz questions to require manual grading is
an interesting possibility, but practically almost useless.

If you set that accidentally, then you are badly stuck. There is no way
to fix it after the students have answered the quiz.

Therefore, we should set the config option to hide that option from the
UI. We do this for all Moodle sites as part of the upgrade, not just for
new installs.

If any admin wants to re-enable this, they can later.
MDL-39412 disabling manual graded behaviour refinements

1. Change behaviour admin settings so you can only select enabled
behaviours.
2. During the upgrade, change admin settings that might be currently set
to manual graded, so that instead they are set to deferredfeedback (if
that is available. If not, we just take the first alphabetically.)
MDL-39412 Prevent developer warnings on upgrade from 24 to master
MDL-39947 mod_forum: Add safety check to variable assignment when counting unread posts
MDL-39971 each attempt builds on last broken for previews.
MDL-40009 notes: corrected the form element names passed to setType
MDL-40018 theme_sky_high: Fixed footer in admin pages.
MDL-36090 core_grade: added logging of overriding of student grades
MDL-39964 report_progress: don't browser sniff for SVG support

Use feature detection, its more robust and better practice.
MDL-25901 rss: do not copyright html tag

They copyright field does not permit html, it should be plain text
MDL-26925 User selector: Set label when no results

Thanks to Jonathon Fowler for the fix!
MDL-37780 fix 1.9 restore on windows
MDL-39832 Files: Revert MDL-39688 commit, 7c742620d26bdba53e136fda293d33b5271ce241

MDL-39688 has been successful in providing a solution for the issue but further
investigations done in MDL-39832 have got the evidence that the given solution
is more likely a workaround.
MDL-39832 Files: Fixed ETag format according with RFC2616.

ETag must be double quoted,
http://tools.ietf.org/html/rfc2616#section-3.11:

      entity-tag = [ weak ] opaque-tag
      weak       = "W/"
      opaque-tag = quoted-string
MDL-37968 course_overview: add dim class to hidden courses for teachers.
MDL-32480 fix display of IMS content packages with external links
MDL-32480 allow external https links in IMSCP too