MDL-42602 remove incorrect snapshot from \core\event\user_loggedin

* all snapshots in events should match the DB data
* the snapshot from user table will not be necessary most probably
MDL-42525 improve performance of plugin listing
MDL-42497 add listing of orphaned subplugin types
MDL-42387 standardise file lifetime handling
MDL-42044 standardise list of unzipped files in add-on installer
MDL-42044 minor add-on installer unit tests cleanup
Merge branch 'wip-MDL-28463-master' of git://github.com/marinaglancy/moodle

Conflicts:
	version.php
MDL-42648 lib: Clean theme throws exception if set_pagelayout is called too late.
Merge branch 'w45_MDL-42387_m26_filelifetime' of https://github.com/skodak/moodle
Merge branch 'w45_MDL-42497_m26_orphanedplugins' of https://github.com/skodak/moodle
Merge branch 'MDL-42546-master' of git://github.com/danpoltawski/moodle
MDL-42215 lang: improved the help string for fullnamedisplay
MDL-42452 block: action menu is now constrained to the block container
MDL-42521 mod_feedback - Feedback does not show line graphs in Clean theme
MDL-42452 ActionMenu: Change constrains mechanism to show the entire menu
Merge branch 'MDL-38850' of git://github.com/rwijaya/moodle
Merge branch 'MDL-42583-master' of git://github.com/ankitagarwal/moodle
Merge branch 'MDL-42664-performance_measuring_filter_manager' of git://github.com/mudrd8mz/moodle
MDL-42452 actionmenu: improved constraint code
Merge branch '42452-26' of git://github.com/samhemelryk/moodle