MDL-37966 Assignment: put upgraded modules where the originals were
MDL-30940 form: Mutiple select work correctly without any selection
MDL-38807 grades: missing setType() calls

In grade category, item and grade forms. Most of these
values are floats handled by format_/unformat_float functions, the
text fields are handled using format_text().
MDL-38807 missing setType warnings on grade screens
MDL-39270 lesson: Reformat module settings form
MDL-39366 book: Section appearance in book module settings
MDL-39158 Increase form label width on wider screens
MDL-37845 multichoice qtype: Fix some display issues.

1. Better handling of multi-line choices in the correct answer display.
2. Remove dangerous CSS that is no longer needed.
MDL-39246 JavaScript: store the time the page starts loading.

This helps synchronise time on the client side with time on the server.
If you wait until a js_init_call runs, you might have had to wait an
unknown number of seconds while all the JS loads. Therefore, we capture
the current time as soon as possible in <head>.

This is a bit like adding .jsenabled to <body> as soon as possible, to
reduce visual flicker.
MDL-39246 quiz timer: compute a more accurate stop time.
MDL-39342 stop users entering too long matching answers.

Since they lead to an ugly DB error.
MDL-39351 collapsed editor had grey bars above and below.
MDL-39322 users: report correct auth method for site administrators
MDL-39335: add an ord() unicode analog to textlib.
MDL-38896 theme_bootstrapbase: Abbreviated weekdays in calendar/renderer.php + added @media css rule for calendar view.
MDL-39377 Increase padding for grouped field labels in question types
MDL-39378 s(): fix bad hex regex
MDL-39378 Improve s() performance.

These changes give about a 10% speed-up in this function. The significant changes are:
1. Simplify the if logic to remove unnecssary cases.
2. Dont pass default argument values to htmlspecialchars, just using the
   defaults is faster.
3. I can confirm that /i regex is faster than the equivalent regex without the i.

I also added more unit tests to test the edge cases.
MDL-39292 use consistent iconsmall in enrol instances UI
MDL-39174 fix phpdocs packages in themes