MDL-45256 portfolio: Unit tests for rewrite pluginfile urls
MDL-45273 quiz: move admin settings into classes folder.
MDL-45273 remove the need for quiz settings.php to include locallib.php.
MDL-45273 only create the quiz settings if necessary.
MDL-45273 quiz: Fix codechecker issues.
NOBUG: Fixed file access permissions
weekly release 2.6.2+
MDL-45221 Allow unit tests to pass under any OS

This commit gets rid of the old lib/tests/other/executable.php
file completely because it was only executable under unix OSs
and moves the check to be performed against some mimetex binaries
that are known to be executable and bundled with every installation.

Note this was discovered because the weekly rolling process changed
the execution permissions of the "fixture" file and, at the end
we decided to get rid of it completely, folowing the plan above.
MDL-42635 lesson: change from error to user friendly message
Merge branch 'MDL-27459-m26' of git://github.com/sammarshallou/moodle into MOODLE_26_STABLE
Merge branch 'MDL-45315-26' of git://github.com/danpoltawski/moodle into MOODLE_26_STABLE
MDL-42956 auth: Fix hard-coded LIMIT clause on keepalive_client method.
MDL-45283 restore: Prevent failure when user course grade exists

When we restore a course, the grade that a user has for the
grade item of the course cannot be created twice. If we try
to create it when it already exists, a database exception is
raised because of index duplication.

The safest way to proceed is certainly to ignore the grade
information from the backup, otherwise we could potentially
overwrite existing information. Though, this only applies
to restore as merge, and it does not affect the update of
the course grade.
Merge branch 'MDL-45256-26' of git://github.com/FMCorz/moodle into MOODLE_26_STABLE
MDL-45256 portfolio: Adding missing global in testcase
Merge branch 'MDL-45256-26' of git://github.com/FMCorz/moodle into MOODLE_26_STABLE
Merge branch 'mdl44575-moodle26' of https://github.com/tlock/moodle into MOODLE_26_STABLE
Merge branch 'MDL-45166_26' of git://github.com/dmonllao/moodle into MOODLE_26_STABLE
MDL-43570 filetypes: Added new filetypes - ddoc, bdoc, cdoc
Merge branch 'MDL-45283-26' of git://github.com/FMCorz/moodle into MOODLE_26_STABLE