MDL-43390 files: Only lock when locking is not prevented
MDL-46206 Accessibility: Remove alt attribute for footer image
MDL-45715 assign: disable marking allocation if markingworkflow is not set.
MDL-46433 blog: fix error message when creating an external blog
MDL-45594 simplify message_get_recent_conversations SQL

I am pretty sure that this new SQL is logically equivalent to
the original, and it passes Mark's unit tests. However, it is
hard to be 100% sure.
MDL-45594 core_message: ordered recent notifications by timecreated
MDL-45594 core_message: added unit tests
MDL-46503 behat: cohort generator allows to create cohort in category
MDL-46504 libraries: Fixing typo
MDL-46506 Assign: fix php warning on grant extension page

This code was missed when the extensionduedate was moved to the userflags table.
MDL-45044 filter_tex: properly escape excutable pathnames for Windows
MDL-43908 mod_assign: Defer notifications for unavailable assignments

Signed-off-by: Tony Butler <tonyjbutler@gmail.com>
MDL-43908 mod_assign: Prevent notifications for unavailable assignments

Signed-off-by: Tony Butler <tonyjbutler@gmail.com>
MDL-43908 mod_assign: Remove redundant code and improve SQL query

Signed-off-by: Tony Butler <tonyjbutler@gmail.com>
MDL-43908 mod_assign: Order submissions by course id then cm id

Signed-off-by: Tony Butler <tonyjbutler@gmail.com>
MDL-46449 fix username prompt in login block when authloginviaemail enabled
Automatically generated installer lang files
MDL-46325 behat: Fixed issue where 'teacher1' didn't exist
MDL-46206 Accessibility: Add aria role to footer image
MDL-46525 enrol_cohort: fix JS error