MDL-41772 - mod_data: Fixed database_module comments not being restored.
MDL-41833 feedback: Fix setType() warning when deleting a response in feedback
MDL-41900 events Log handler failures
MDL-37973 gradebook Return a maxgrade of '-' if grade type is TEXT

Including tests for correct return from
grade_edit_tree_column_range->get_item_cell()

This commit includes some special code just for 2.4 in the test
related to a bug in assign.
MDL-41907 Repositories: Maintain the sortorder of a file when overwriting it.
Automatically generated installer lang files
Merge branch 'wip-MDL-41772-24' of git://github.com/abgreeve/moodle into MOODLE_24_STABLE
MDL-36465 Course JavaScript: Ensure that the zero section is not draggable
Merge branch 'MDL-41833-m24' of git://github.com/ankitagarwal/moodle into MOODLE_24_STABLE
MDL-41929 quiz statistics, overall stats not displayed.
Merge branch 'MDL-36465-24' of git://github.com/andrewnicols/moodle into MOODLE_24_STABLE
Automatically generated installer lang files
MDL-41894 feedback: Remove unused code, which is generating warnings
MDL-40903 cache: converted persistent into persistentdata

At the same time all cache instances were made persistent
MDL-40903 cache: coding style tidyup pre-integration
MDL-40903 cache: Unittests and small fixes for persistent application cache
MDL-40903 cache: fixed up event invalidation
MDL-40903 cache: renamed persistcache to staticacceleration
MDL-40903 cached: fixed up versions
Merge branch 'MDL-41929_24' of git://github.com/timhunt/moodle into MOODLE_24_STABLE