MDL-46753 auth_cas: Replace hardcoded logout_return_url to user defined URL.

Credit goes to Mitsuru Udagawa, thanks!
MDL-46842: Reopen assignment submissions when using offline grading worksheet
MDL-46477 chat:hard coded string in mod/chat
MDL-46867 filter_glossary: don't use static for one-time JS.
MDL-46868 glossary / filter: performance, check modinfo sooner.

Since we need to check modinfo anyway, do that as soon as possible so we
can get a performance win if there are no glossaries in the course.
MDL-46816 mod_asssign plagiarism: Remove unnecessary code.
MDL-46716 core_calendar: Replaced iCal image with stylised text
MDL-46509 enrol: fix usage of incorrect enrol plugin in capability check
MDL-46509 enrol: fix usage of incorrect capability check
MDL-46509 enrol: Require 'enrol/PLUGIN:config' capabilities to show/hide enrollment instances
MDL-46235 ddl: add support for large number of text fields in one database table
Merge branch 'master_MDL-46816' of https://github.com/danmarsden/moodle
Merge branch 'MDL-46867' of git://github.com/timhunt/moodle
Merge branch 'MDL-46868' of git://github.com/timhunt/moodle
Merge branch 'master_MDL-46842' of https://github.com/greg-or/moodle-mod_assign
Merge branch 'MDL-46753-master' of git://github.com/lameze/moodle
Merge branch 'm28_MDL-46716' of https://github.com/totara/moodle

Conflicts:
	theme/bootstrapbase/style/moodle.css
Merge branch 'MDL-46477' of https://github.com/shashirepo/moodle
MDL-46842 assign: Fix for unit tests - previous patch was completely ignoring manually reopening attempts.
Merge branch 'MDL-46509' of https://github.com/danielneis/moodle