MDL-45432 mod_assign Declare character encoding in onlinetext export

Signed-off-by: Tony Butler <tonyjbutler@gmail.com>
MDL-45469 Conditional availability: Restrict by text area broken

It has never worked, because the data for text area fields is not
loaded into the $USER object.

Changing it so that the dropdown list does not include these types
of field. (This 2.6 version of change is similar to the 2.7 code
but in a different location and without unit test.)
MDL-45496 core Added space to logged in as line
MDL-45512 comments: Added full date to comment details.
MDL-37838 block_courseoverview: fix pluaralisation logic

Note that this kind of handling of plurals is extremely limited, see:

https://moodle.org/mod/forum/discuss.php?d=85897
http://search.cpan.org/~petdance/Locale-Maketext-1.12/lib/Locale/Maketext/TPJ13.pod

However, this is a simple fix to the existing logic
MDL-45525 themes: minor forum improvements

Fixed an RTL style that wasn't kicking in properly on 2.6 and 2.7; backported to 2.5.
MDL-44027 groups: remove some junk html
MDL-45545 csslib: Chunking handles commas in media query definitions
MDL-45546 mod_forum: Login the user before getting its context
MDL-45535 CSS chunking breaks media rules if CSS invalid (IE)

Invalid CSS with extra } symbols, which previously (by fluke)
worked, was broken by recent chunking improvements. This change
makes the chunking code robust against this (stupid) situation.
MDL-45323 grade: Fix query errors on grade_get_grade_for_activity method.
MDL-45323 grade: Unit test for grade_get_grade_items_for_activity()
MDL-45583 badges: check parent contexts consistantly when checking required role.
MDL-41109 dndupload: Add missing error string
MDL-44333 quiz reports: use consitent name for user pref

The Marks for each question setting was not being saved properly as a
user preference.
MDL-45603 cache Fix the mappingsonly option to work as advertised.
MDL-44711 navigation: better handling of course expansion exception
MDL-45605 Phpunit: Do not call gc_collect_cycles as part of reset.

This takes 25% of the time in running tests and there is no benefit. The
behaviour of destructors is the same before/after the patch.

Conflicts:
	lib/phpunit/classes/util.php
MDL-44449 quiz access rules should have a delete hook.

So they can clean up their settings when the quiz is deleted.

See
https://github.com/moodleou/moodle-quizaccess_honestycheck/commit/babf149c2cc6dd734c272cd332b2032cc19db7d8
for an example of using this.
Merge branch 'MDL-37838-25' of git://github.com/danpoltawski/moodle into MOODLE_25_STABLE