MDL-44328 theme_bootstrapbase: Improved clean theme calendar styling.
MDL-44328 theme_bootstrapbase: Re-defined colour variables making new ones where needed;
MDL-44499: Fix PHP warning in upload_manager class
MDL-44550 Docs: Remove comment about mysql_lock_factory from config-dist.php
MDL-44588 quiz: fix crazy variable called $this.
MDL-44433 lang: Update the name of country code CV

ISO-3166 has updated this name to Cabo Verde:
https://www.iso.org/obp/ui/#iso:code:3166:CV
MDL-44610 enrol Enable autoloading of enrolment plugins
MDL-44416 Correct detail view paging
MDL-41115 add option to allow login via email
MDL-43604 add support for future hacky MariaDB versions

This patch also shows the real server version without
normalisation on the environment page, this should
hopefully help people to identify MariaDB...
MDL-44191 hack around MySQL 5.6 inability to lower auto_increment
MDL-44339 treat unexpected debugging() calls in phpunit tests as errors
MDL-44432 use new task scheduler in new logging plugins
MDL-42890 tool_log Default legacy reader should handle CRUD queries
MDL-42890 backup: Remove usage of log table in backup cron helper
MDL-44500 detect context-courseid inconsistencies in new events
MDL-44515 import latest PHPExcel 1.8.0
MDL-44516 import htmlpurifier 4.6.0
MDL-44521 import TCPDF 6.0.062
MDL-44522 import markdown 1.4.0