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-47266 quiz: fix restore log message.
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-47270 core_component: make cache independent of filesystem ordering
MDL-46991 Availability: Conditional dates not updated on restore
MDL-47224 qtype_calculated: Calculated qtype comment on datasetitems should follow formatting rules
Automatically generated installer lang files
MDL-40006 searchableselector does not work in IE or Safari.

This fix is a horrible hack, but one I have used for years in tool_editrolesbycap
https://github.com/moodleou/moodle-tool_editrolesbycap/blob/master/yui/capabilityformfield/capabilityformfield.js
and it seems to be reliable.

As an added bonus, I removed the use of YUI2 here.

Also, I fixed the related button in quiz to be GET not POST.
Automatically generated installer lang files
MDL-47238 core_user: added an error message if guests access user profiles and they aren't allowed to
MDL-47269 yui/src/dock: Invert dock reset blocks icon, in RTL mode
Merge branch 'MDL-46991-m27' of https://github.com/sammarshallou/moodle into MOODLE_27_STABLE
Merge branch 'MDL-40006_27' of git://github.com/timhunt/moodle into MOODLE_27_STABLE
Merge branch 'MDL-47270-core-component-classmap-ordering_27_STABLE' of https://github.com/mpetrowi/moodle into MOODLE_27_STABLE
Merge branch 'MDL-47238_guest_27' of https://github.com/andyjdavis/moodle into MOODLE_27_STABLE
MDL-37998 quiz settings: disableif rules should account for overrides.

Some form fields are disabled if only one attempt is allowed. However,
there may be an override allowing some students more attempts. We need
to account for that possiblity when setting up the disabled if rules.

Note the disabledIf is good for usability on this complex form, which is
why I don't just want to get rid of them.
Merge branch 'MDL-47266_27' of git://github.com/timhunt/moodle into MOODLE_27_STABLE
Merge branch 'MDL-47269_M27' of https://github.com/nadavkav/moodle into MOODLE_27_STABLE
Merge branch 'MDL-47182-27' of git://github.com/danpoltawski/moodle into MOODLE_27_STABLE