MDL-41000 Events: Fixed phpdoc for get_name and get_description in \core\event\base class
MDL-30852 grade report: Add aria attributes

Converted to git branch by Damyon
MDL-30852 grade: Coding style fix for user report.
MDL-41000 Events: Fixed return values for get_name() and get_description() in existing events

Changes done for following events:
- \core_auth\event\user_loggedin
- \core\event\role_assigned
- \core\event\role_unassigned
MDL-36002 dragdrop: focus fix and exception catching

This sets the focus correctly after a cancel or drop event.
It also catches exceptions from the lock/unlock functions.
MDL-40947: Fix segmentation fault issue in get_fast_modinfo.
MDL-40997 phpunit: Assertions for events legacy data
MDL-40889 prevent 304 when minimising JS
MDL-40815 deprecate events_trigger()
MDL-31226: quiz: Fix message for attempts built on previous.

At the moment, when attempt is built on the last one, "not yet answered"
message is shown, which confuses many people. This patch modifies the state to
"complete" for attempt based on previous and modifies the output string.

Many thanks to Tim Hunt for guiding me through quiz infrastructure and some code
suggestions.
MDL-41017 improve purify caching

The improvements include:

* HTMLPurifier cache is stored in localcachedir
* allowobjectembed changes are not ignored any more
* the cache keys include revision and all options which makes
  this suitable for local caches on cluster nodes
* unchanged test is replaced by "true" value which should
  significantly improve performance
* removal of purge_all_caches() hack for directory recreation
* comments and coding style cleanup
MDL-40995 simplify minify integration and fix all known issues
MDL-41020 fix installer notices
MDL-40943 use observer priority only inside group of observers

This makes the '*' observers to be executed always first. This change allows us to implement parent event class catching if we ever decide we need it without breaking BC. This change includes some more unit test fixes.
MDL-41002 fix typo causing fatal error on other users page

Credit goes to Bernhard Brandstetter, thanks!
MDL-40940 try to guess testcase location using info from /phpunit.xml

This will help with core tests in non-standard core subsystem locations.
MDL-40901 standardise core test case class and file names

This finally allows us to type only the class name when executing individual core test cases.
MDL-40901 use assertInternalType()
MDL-41024 lib: deprecate isediting
MDL-41025 moodlelib: addressed todo on truncate_userinfo