MDL-44118 new environment check are all quiz attempts upgraded.

In Moodle 2.1, there was a major DB upgrade relating to questions, and
it was possible to delay some of that upgrade. Now, those DB tables are
changing again, and the time has come to insist that all the updata has
been upgraded (or deleted).
Merge branch 'MDL-43337-26' of git://github.com/FMCorz/moodle into MOODLE_26_STABLE
Merge branch 'MDL-43265_26' of https://github.com/jacks92/moodle into MOODLE_26_STABLE
MDL-43265 question: incorrect closing parenthesis
Merge branch 'MDL-43182_26' of git://github.com/mr-russ/moodle into MOODLE_26_STABLE
Merge branch 'MDL-44118_26' of git://github.com/timhunt/moodle into MOODLE_26_STABLE
MDL-43930 assign: Do not log when user is logged in as someone else.

I do not agree with this behaviour - but this makes it consistent with other modules.
Merge branch 'install_26_STABLE' of git://git.moodle.org/moodle-install into MOODLE_26_STABLE
weekly release 2.6.1+
MDL-44288 qtype_calculatedsimple fix validation notice.

The notice happend if you clicked Save changes before Find the wild
cards {x..} present in the correct answer formulas.
MDL-44279 user: added unit test to trigger known bug
MDL-42279 user: fixed typo in user_get_user_details_courses
Automatically generated installer lang files
MDL-44286 behat: Updating to our custom Syn library
MDL-43882 performance: New metric, time spent by the database

This patch adds a new performance metric to the performance
info shown by MDL_PERF* vars, the time spent by the database,
it was one of the wonderful @poltawski ideas. To be more specific
the value displayed is the sum of the time elapsed between query_start()
and query_end().
MDL-43882 dml: New test for perf_get_xxxx() methods
MDL-44111 behat: Limiting dump files filename size
MDL-43837 behat: Adding reduced timeouts

There are steps where we want to check that
"something" does not appear in the page
or does not exist. We still have to spin
but we don't need to spin for 6 seconds.
Merge branch 'MDL-41767-26' of git://github.com/FMCorz/moodle into MOODLE_26_STABLE
MDL-44217 theme_bootstrapbase: darkend link colour by 5% for accessibility