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-47224 qtype_calculated: Calculated qtype comment on datasetitems should follow formatting rules
Automatically generated installer lang files
Automatically generated installer lang files
MDL-47269 yui/src/dock: Invert dock reset blocks icon, in RTL mode
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
Merge branch 'MDL-47242-27' of git://github.com/jethac/moodle into MOODLE_27_STABLE
Merge branch 'MDL-46811-27' of git://github.com/danpoltawski/moodle into MOODLE_27_STABLE
MDL-47180 qformat_webct: Import of calculated questions broken
Automatically generated installer lang files
Merge branch 'MDL-47180_27' of git://github.com/jmvedrine/moodle into MOODLE_27_STABLE
MDL-47180 qformat_webct: whitespace cleanup
Merge branch 'MDL-47224_27' of git://github.com/aolley/moodle into MOODLE_27_STABLE
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-47242 theme_bootstrapbase: inverted color and RTL fixes