MDL-42065 core_grade: Modified some grade_item queries for improved performance

* Modified 2 queries in grade_item::depends_on to improve performance
* Added additional unit tests to cover those queries better
Automatically generated installer lang files
MDL-42380 Course unit tests: Remove assert causing oracle unit tests to die
Merge branch 'MDL-42065_master' of https://github.com/sam-moodle/moodle
Merge branch 'MDL-42380-master' of git://github.com/damyon/moodle
MDL-43411 Backup: Fix restore from 1.9

The restore progress bars introduced a bug when restoring Moodle 1.9 backups.
build_plan needs to be surrounded with start_progress/end_progress with the mode
set to indeterminite or it throws coding errors.
Merge branch 'MDL-42411-master' of git://github.com/damyon/moodle
Merge branch 'install_master' of git://git.moodle.org/moodle-install
NOBUG: Fixed file access permissions
Moodle release 2.6beta
MDL-42117 JavaScript: Don't rely on node data for course toolboxes

The YUI versions of getData and setData do not store the data in the DOM,
but in an instance of YUI. If you make modifications in one instance, but
apply them in another, then the data values are not accessible between
these two instances.

Additionally, there's no benefit to storing the instances on
initialisation - if anything, it increases the load overhead.

This change moves toolboxes to calculating their ancestors on click in the
same way it was done in the initialiser.
MDL-42117 JavaScript: Ensure that new activities are fully set up

We don't need to set up anything specifically for toolboxes any more, but
other third-party JS may require additional setup following new module
creation.