MDL-43259 JavaScript: Deprecate M.core.dialogue's lightbox attribute

The lightbox attribute just sets the modal attribute of the upstream
dialogue and provides no real benefit. We should deprecate it in favour of
documented upstream attributes of Y.Panel.
MDL-25473 mediaplayer - prevent embedded videos from looping
MDL-39725 database: Add statistics collection functions
MDL-39725 database: Include stats collections in unit tests
MDL-39725 database: Apply database statistics update to daily stats
MDL-43259 JavaScript: Stop using deprecated lightbox config setting when instantiating dialogues
MDL-34321 Assignment2.2 - Fixing submission count
MDL-36984 Assign: Add redirect after saving grades
MDL-38832 course: remove unused constants
MDL-43268 fix filter notice when not in debug mode
MDL-43322 JavaScript: Include moodle-core-popuphelp in the mcore rollup

moodle-core-popuphelp is used on every page in Moodle, so it should be
included in the rollup by default to save a request each time.
MDL-41075 Remove "Choose..." option from participants page.
MDL-43322 JavaScript: Correct cache-base entry in base rollup
Merge branch 'w51_MDL-43268_m27_filternotice' of https://github.com/skodak/moodle
Merge branch 'MDL-36984-master' of git://github.com/phalacee/moodle
Merge branch 'MDL-34321-master' of git://github.com/phalacee/moodle
Merge branch 'MDL-25473-master' of git://github.com/phalacee/moodle
Merge branch 'MDL-39725_analyze' of https://github.com/mr-russ/moodle

Conflicts:
	lib/dml/moodle_database.php
Merge branch 'MDL-41075-master-3' of git://github.com/mouneyrac/moodle
MDL-43295 mod_assign: Removed wrongly used format_text call in online text submission.