MDL-38565 cache: cron routine to clean up old session data
MDL-38565 cache: upgrade code to amend default stores

Conflicts:
	version.php
MDL-38565 cache: improve stats gathering
MDL-38565 cache: tidy up pre-integration

Conflicts:
	lib/db/upgrade.php
Merge branch 'MDL-39135-24' of git://github.com/damyon/moodle into MOODLE_24_STABLE
Merge branch 'MDL-39185_m24' of https://github.com/markn86/moodle into MOODLE_24_STABLE
MDL-30940 form: Mutiple select work correctly without any selection
Merge branch 'MDL-39167_24' of git://github.com/timhunt/moodle into MOODLE_24_STABLE
Merge branch 'MDL-39084-moodle24' of github.com:StudiUM/moodle into MOODLE_24_STABLE
MDL-39050 quiz access rules: settings.php files should work.
Merge branch 'wip-MDL-38565-m24' of git://github.com/samhemelryk/moodle into MOODLE_24_STABLE
Merge branch 'MDL-38361_24' of https://github.com/prateeksachan/moodle into MOODLE_24_STABLE
Merge branch 'MDL-39219_scorm_ie7_24' of git://github.com/davosmith/moodle into MOODLE_24_STABLE

Conflicts:
	mod/scorm/module.js
Merge branch 'MDL-39172_24' of git://github.com/jmvedrine/moodle into MOODLE_24_STABLE
Automatically generated installer lang files
Merge branch 'MDL-39050_24' of git://github.com/timhunt/moodle into MOODLE_24_STABLE
Merge branch 'w16_MDL-39141_m24_toolbar' of git://github.com/skodak/moodle into MOODLE_24_STABLE
MDL-37942 Images with non-alphanumeric chars in file name won't export
MDL-34933 core_message: Adding index to improve database access on message_working table.
MDL-37514 module.js: fix .js for auto quiz submission in preview mode

The issue: when we attempt the quiz as teacher/admin and timer is up,
quiz is not submitted, even though "Open attempts are submitted
automatically" is set. I've changed the javascript for a timer,
responsible for submission, removing the special behaviour in case of
preview mode. Note, that when the admin/teacher is taking a quiz, the
"preview" mode is automatically switched on.

It is a bit strange, since in the javascript there was clearly no
expressed intention to really submit quiz in preview, even when timer
hits. It does not really seem like a accidental bug, rather it looks
like some misunderstanding. Worse still, it may happen that I did not
understand the intentions of previous editor and ruined some
functionality. Because of this, and the fact that this is my first bug,
I would like to ask about the peer review! Please, see my comments in
bug discussion for the testing steps.