MDL-44748 Atto: Make it the default on upgrade.
MDL-44945 mod_workshop: fixed event snapshot
MDL-44940 quiz editing page problems from MDL-43749.

* If the quiz starts with an empty page, you could not move the first
question up onto it.
* Adding page breaks in the middle sometimes added them in the wrong
place.
* Adding a new page at the end is problematic, and here we fix it as
much as possible, by letting you move the last question down to create a
new page. This needs MDL-40987 to be fixed properly.
MDL-44967 upgrade: fixed theme removal when themes have been removed already
MDL-41511 blocks: improved how custom block regions were being rendered.

There is a new theme property 'blockrendermethod' that can be set by the
theme in its config.php and tells Moodle what method it is using to render
blocks in the layout files.
Either blocks, or blocks_for_region.
Then when adding custom block regions to a page content we ensure we use
the same method the theme is using elsewhere.

This is really a hack becuase we (I) didn't properly deprecate
blocks_for_region when I added the blocks method.
MDL-41551 blocks: added tracking and recognition of custom block regions
MDL-41551 theme_base: improved custom block region handling for base
MDL-44882 always set maintenance mode on non-cached admin pages

This should resolve all issues with themes during upgrades.
Merge branch 'MDL-44940' of git://github.com/timhunt/moodle
Merge branch '41551-27' of git://github.com/samhemelryk/moodle
MDL-44758 editor-atto: prevent table-in-table creation

Prevent new table creation, displaying table context menu instead when cursor is within caption, when multiple cells are selected, when selection contains both nodes within and outside of the table, and when selection contains nodes from multiple tables.
Merge branch 'wip-mdl-44945' of https://github.com/rajeshtaneja/moodle
Merge branch 'MDL-44758-master' of git://github.com/jethac/moodle

Conflicts:
	lib/editor/atto/plugins/table/yui/build/moodle-atto_table-button/moodle-atto_table-button-min.js
Merge branch '44967-27' of git://github.com/samhemelryk/moodle
Merge branch 'MDL-44748-master' of git://github.com/damyon/moodle
Merge branch 'w15_MDL-44882_m27_upgrademaint' of https://github.com/skodak/moodle