MDL-41593 admin: use default setting if preventexecpath active

This resolves problems when installing Moodle
and addons when preventexecpath active.

Please note the admin_setting_configfile is still
incorrectly restricted - this will be resolved by
MDL-40949.
MDL-38065 gradebook: Fix issue with hidden categories breaking rowspan.

Hidden subcategories break the rowspan in the gradebook; this fix corrects
the calculation of the rowspan.
MDL-46133 tool_monitor: added event cleanup task
MDL-46133 tool_monitor: added unit tests
MDL-47664 phpunit: Do not use sequence number changes for Oracle

When resetting a sequence number, we call change_database_structure()
which in turns clears the MUC cache for databasemeta. This cache contains
information about the table, columns, etc.

After the cache is cleared, it must be re-filled, and it was discovered
that the get_columns() code which fills this cache can take a particularly
long time. Given that this is called for every table in Moodle, this can
add up to a significant period, and this is done on a per-testsuite basis.

On my SSD install this was taking approximately 40 seconds on each re-fill
of the cache.
MDL-47363 Grades: Style for the User report
MDL-47363 Grades: Style for the Setup grades
MDL-47290 Grades: Style for the Single view table
MDL-47290 Grades: Minified CSS and applied coding style standards
MDL-47290 Grades: added bold for course total
MDL-47737 editor_atto: Prevent false negative when saving draft on IE9
Revert "MDL-47684 mod: better validation of rating options"

This reverts commit 8028df293a4f024a954dc12ed4e6cb5161c951b0.
NOBUG: Fixed file access permissions
on-demand release 2.8beta+
Merge branch 'MDL-47363' of git://github.com/marinaglancy/moodle
on-demand release 2.8beta+
MDL-38172 Lesson: Additional Info not displayed at end of lesson
MDL-47735 core: prevented iteration of 'groupmembersonly'

The course module variable 'groupmembersonly' was removed in 2.8.
MDL-47728 tool_monitor: added capability check before displaying link
MDL-47754 install: fix redirect loop