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-47564 Availability: incorrect use of defined('PHP_UNIT')
MDL-47572 libraries: modify unittest to avoid random timing fail

Thanks to Nigel Cunningham
MDL-47583 tinymce_managefiles: correctly decode filename
MDL-47583 atto_managefiles: correctly decode filename
MDL-47594 core_accesslib: removed three useless lines of code
MDL-47431 advanced grading: correct use of frankenstyle names for consistency
MDL-44548 mod_scorm: force an external sync to check for updated files.
also remove some globals no longer needed (not used in function or in required files.
MDL-47613 wiki: allow searching several words

Thanks to Sandeep B for suggested solution
MDL-47631 report_participation: fixed filtering by letter
MDL-47646 CURL redirect unit test: handle broken servers
MDL-46599 gradebook: Unit tests for last exported date and force import option
MDL-18229 gradebook: Initial commit of LSUs Quick Edit Plugin

Renamed to Single View in MDL-47289.
MDL-18229 gradebook: Added filter icons for activities and users.

Corrected CSS for grades column, was far too large.
MDL-18229 gradebook: Single view navigation corrected.

Usernames link to user profiles.
Activities to their activity page.
MDL-47347 added basic navigation to top and bottom of gradereport_singleview

Part of MDL-18229
MDL-18229 gradebook: Linking activities and usernames correctly.

Activities to their course page and usernames to their
profile page as per standard.
MDL-18229 gradebook: Fix for loading activities.

Was using local variable iteminstance rather than cmid.
MDL-18229 gradebook: Renaming of Single_view to Single view
MDL-18229 gradebook: Links to Single view via icons on Grade Report.