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
MDL-42240 assignfeedback_editpdf: improve ghostscript debugging
Automatically generated installer lang files
MDL-42224 clean up message and email redirection testing
MDL-42302 course: fixed bugs while changing visibility

* No longer uses show which is resvered on MySQL
* Selected category courses are now always returned.
Merge branch '42302-26' of git://github.com/samhemelryk/moodle
MDL-42302 course: re-shitfering management module.
Merge branch 'MDL-42240' of git://github.com/danpoltawski/moodle
Merge branch 'w42_MDL-42224_m26_msgredir' of https://github.com/skodak/moodle
Merge branch '42294-26' of git://github.com/samhemelryk/moodle
MDL-42029 Editpdf: Page selector should indicate what page you are on
Merge branch 'MDL-42029-master-nomerge' of git://github.com/mouneyrac/moodle

Conflicts:
	mod/assign/feedback/editpdf/lang/en/assignfeedback_editpdf.php
MDL-42380 Course unit tests: Remove assert causing oracle unit tests to die
MDL-42224 fix log output regression in auth test
MDL-42148 new overview of 3rd party libraries

Includes:
* each plugin has own thirdpartylibs.xml file
* added missing libraries
* fixed existing library infos
* new Site administration / Development / Third party libraries page
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