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-35530 Lesson Module: Add question text to facilitate grading
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-36490 theme_standard: reduces the 15px radius down to 3px in style/css3.css for .generalbox objects
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-36736 course: Availability information will use hide class for hidding
MDL-36736 course: Availability information should not be visible for hidden modules

If user is viewing hidden module, availability information should only be visible to
user when editing and module is visible. If editing and module is hidden, then hide
availablilty information as it's invalid.
When user is not editing and activity is hidden then don't add availability information.
MDL-36704: wrap pending conditions in span tags
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-36812 - Enabling grade_report_fixedstudents, shows the user's list on the left side of the page, in RTL mode (theme/standard)
MDL-30899 moodle-core-notification Replacing Y.Overlay for Y.Panel

References to lightbox are still there to maintain the same
external API but are converted to a modal attribute internally,
same with closeButton, now it uses the Y.Panel close button
MDL-30899 modchooser Changing from overlay to panel references
MDL-30899 block_community Changing from overlay to panel references
MDL-30899 moodle-core-notification Adding H1 to notifications headers
MDL-30899 moodle-core-notification Adding focus to non modal windows
MDL-30899 moodle-core-notification Adding close button title for accessibility