MDL-38367 course dndupload - various tweaks to the UI

Switched to Moodle-style dialog boxes (thanks Andrew for the pointer)
Enter button now submits the form (from within the 'name' field)
Upload button is disabled when the name is empty (if the name is required for the selected handler)
Dialog now has 'What do you want to do with this text?' and 'Name' for the text
Entire course section now has a class added when you drag over it (to enable it to be styled in the future)
MDL-38367 course dndupload - workaround to allow 'add X here' text to be drop target in Firefox
MDL-38431 comment: Pass formated comment created time to JS and print_comment
MDL-38431 comment: profile url should be escaped, as it's used in html
MDL-38435 form: Sections can be expanded by default
MDL-38340 form: Last fieldset is collapsed by default
MDL-36872 reports: Fixing incorrect sorting of recent activites by timestamp
MDL-36395: Converted hard-coded MAX_USER_PER_PAGE to config setting

course, cohort, enrol, role, groups and forum used to use hard-coded
MAX_USERS_PER_PAGE=100 for rendering user list. This has been converted
to $CFG->maxusersperpage.
MDL-38426 mod_label - correctly handle plain text that has been added by drag and drop upload
MDL-38049 form: Collapsed sections are hidden on page load
MDL-37959 form: Aria attribute set on collapsible sections
MDL-38453 form: RTL styles for short forms
MDL-38456 Allow colons in paths passed to mdeploy.php utility

The input_manager now accepts colons (:) in TYPE_PATH options, but only
in cases where the colon is used as a part of Windows drive labels, as
in C:\apache.
MDL-38215 Fix cross-db support in workshop SQL queries

The $sql used in these methods may contain multiple parts glued
together by the UNION operator. Simply appending the ORDER BY statement
to the end of the query does not work in all DBs (failure reported at
Oracle). Following the pattern already applied in MDL-30051, we wrap the
SQL into yet another SELECT statement and perform ordering there.

Credit goes to Sara Cenni for suggesting the fix.
MDL-38368 folder: No edit button when displayed inline
MDL-38397 question editing: only validate default mark if present.

Most qtypes have that field, but not all. multianswer is an example in core.
Also some contrib qtypes.
MDL-38005 form: Headers have a proper name
MDL-30790 - Option to collapse or expand sub-folders
MDL-25655 glossary: non full searches now working.

In the process of updting the module from 1.9 to
2.0 the (non) full search feature was lost without notice.

This restitutes it with the same behavior present in 1.9:

- fullsearch disabled: look into concepts and aliases.
- fullsearch enabled (default): look also into definitions.
MDL-38320 fix role name display when roles switched