MDL-44670 themes: Updated screenshots of Clean and More
MDL-44590 category: correct get_string component
MDL-44590 behat: Add test for course category idnumber duplication
MDL-44739 theme_more: Set default theme settings
MDL-44745 Assign: Make the grading table use the fullname function from the assign class.

This will take blind marking into account when displaying student names.
MDL-44745 Assign: Fix typo in assign->fullname function

This is a new function on master only.
MDL-44804 editor_atto: JS error when filepicker is disabled
MDL-44822 assignfeedback_editpdf: Stop test generation in is_enabled()

This change also moves one of the checks in test_gs_path. If
generateimage is false, there's no need to stat for the fixture file.
MDL-44701 gradereport_grader: Display warning on navigation if unsaved grades are present
MDL-44837 Behat: 'dialogue' selector only works for confirm dialogues

The dialogue selector in Behat (used only in one place) didn't work for
other types of standard Moodle notification dialogue.
MDL-44733 add support for disabling of scheduled tasks
MDL-44715 use parent::validate_data() consistently in all events

Includes some minor PHPDocs typo fixes.
MDL-44754 Atto: Explaining what group names are used for in toolbars
MDL-44808 atto_table: Remove accessibility information from dialogue
MDL-44811 quiz settings form title: change for consistency.

Thanks to Fred for poining out that most other activities use the work
Appearance for these sorts of settings.
MDL-44746 core_events: removed incorrect uses of snapshots
MDL-44746 core_events: minor changes to the user_deleted event
MDL-44862 always add dbport to dbsocket in pg driver

This should hopefully resolve problems when using sockets connection
to pg servers running on non-standard ports.
MDL-44862 postgres: tests to support socket & port

Both the database auth and enrol plugins use ADOdb
to perform connections. Socket and port are allowed
there if passed as "socket:port", so, when both are
configured in CFG, we pass them that way. Else
ADOdb defaults to standard port (5432).
MDL-44759 atto_undo: Buttons are only enabled when needed

Before the patch it was happening that the undo or redo buttons
were enabled even though clicking on them didn't produce anything.
This is partly because we were not storing the initial value, we
allowed for the stack to be empty, and we were using not clean
HTML.