MDL-29938 implement core_user_get_users as unification

unifies core_user_get_users_by_id and get_course_user_profiles

Conflicts:

	user/lib.php
MDL-35543 modify get_users to get_users_by_field (more complex search function named get_users will be implemented later - focussing yet on retrieving user info for a specified field)
MDL-35230 AJAX Only load head and footer javascript if it present
MDL-31750 - course: Creating a consistent api for checking permissions for moving courses to different categories.
MDL-31750 - course: Unit tests for the function can_move_courses_to_category().
MDL-36357 cleanup - remove double semicolons
MDL-35842 - Glossary, Blocks - Joseph Rézeau's patch for setting the Random Glossary block to progress alphabetically
MDL-36741 mod_forum: fixed SQL that was generated when either timed posts or groups were enabled
MDL-35816 - File picker - Adding ALT attributes to the icons of the file picker
MDL-3941 auth/cas auth/ldap enrol/ldap Add support for LDAP-TLS.

Credit goes to Chris Bandy for proposing the initial patch.
MDL-27901 navigation: Notice when an admin node name is already used
MDL-32639 files: Removing '0' start folder in archives created with filemanager
MDL-32639 files: Improved File Manager download and zip support
MDL-32639 files: Zipping a folder does not overwrite existing files
MDL-28585 LDAP Auth doesn't handle password expiration

All credit goes to Mark Ward for proposing the initial patch.

Signed-off-by: Iñaki Arenaza <iarenaza@mondragon.edu>
MDL-36456 repository: S3 handles errors in a nicer way
MDL-36966 Assignment: Bug - Student submission appears graded by themselves.

Fix a bug when a student editing his submission after it has been graded, it changes the 'graded by' details to the student's name in the feeback summary
Automatically generated installer lang files
MDL-37037 assign Show message if no files to download
MDL-37037 Assignment Some minor refactoring of the previous patch

This just makes the control flow a bit easier to read.

I also added a continue button to take you back to the grading page.