MDL-46811 update download.moodle.org url to https

https is now the prefferd protocol for this site
MDL-47242 theme_bootstrapbase: fix nested custom_menu responsive display
MDL-47244 theme_bootstrapbase: fix custom_menu dividers under responsive layouts
MDL-47248 Use new Moodle logo for RSS feeds generated by Moodle

Themes can override this logo as any other core pix file. The new logo copied
from https://moodle.org/logo/ and resized to match the previous logo size
(140x35px).
MDL-46313 mod_forum: Replace subscription status icons
MDL-46523 navigation: add body class when roleswitched and not in initial install
MDL-47182 admin: warn about delayed scheduled tasks

Rather than using module cron, use scheduled tasks to work out
if cron has been running recently.

This is not perfect, the admin could disble all tasks, or reschedule
them - but its not complex to compute.
MDL-46313 forum: Move discussiontoggle CSS to module
MDL-46937 modinfo: Allow course format to overwrite section availability
MDL-47266 quiz: fix restore log message.
MDL-47240 Modinfo: Section info accesses nonexisting property groupingid

This code wasn't actually used, so we should remove it.
MDL-47224 qtype_calculated: Calculated qtype comment on datasetitems should follow formatting rules
MDL-47269 yui/src/dock: Invert dock reset blocks icon, in RTL mode
Merge branch 'MDL-47266' of git://github.com/timhunt/moodle
Merge branch 'MDL-47269_master' of https://github.com/nadavkav/moodle
Merge branch 'MDL-46523-master' of git://github.com/jethac/moodle
Merge branch 'MDL-46313-master' of git://github.com/andrewnicols/moodle
Merge branch 'MDL-47182-master' of git://github.com/danpoltawski/moodle
Merge branch 'MDL-47242-master' of git://github.com/jethac/moodle

Conflicts:
	theme/bootstrapbase/style/moodle.css
MDL-47252 mod_forum: Ensure guest users can't subscribe to discussions