MDL-43266 Testing sites are cleaning all test dataroot contents
MDL-44499: Fix PHP warning in upload_manager class
MDL-44246 behat: New mod_quiz test when JS is disabled
MDL-43266 testing: Removing duplicated keys
MDL-44588 quiz: fix crazy variable called $this.
Merge branch 'MDL-43266_26-last-fixes' of git://github.com/dmonllao/moodle into MOODLE_26_STABLE
MDL-43960 assign: Add missing include

There was a report of mod_assign_save_grade webservice failing because of this.
I couldn't reproduce it, but grepping the code found one place where this include
should be added.
MDL-44433 lang: Update the name of country code CV

ISO-3166 has updated this name to Cabo Verde:
https://www.iso.org/obp/ui/#iso:code:3166:CV
MDL-43266 testing: avoid assoc arrays for json

Last commit switched from raw arrays to associative
arrays. That leads to json_encode() to generate an
object instead of an array, ultimately leading to
problems with the rest of code expecting an array.

By using array_values() we are moving back to the
non-associative array.

Also, fix some file permissions.
weekly release 2.6.2+
MDL-44416 Correct detail view paging
MDL-44191 hack around MySQL 5.6 inability to lower auto_increment
MDL-44299 resolve collision with session_gc() in PHP 5.6
MDL-44339 treat unexpected debugging() calls in phpunit tests as errors
MDL-44516 import htmlpurifier 4.6.0
MDL-44624 fix false failures in DML tests
MDL-44585 grade_import: Restrict the accepted types in the gradebook import
MDL-44502 filelib: Add mimetype for Maple worksheets
	modified:   core.css
MDL-44356 theme_bootstrapbase: Centralize the drag and drop arrow in filemanager.