MDL-38102 lib: Check for null return value from password_hash function call
MDL-37966 Assignment: put upgraded modules where the originals were
MDL-38480_m Fix for messy usage of language strings in block course overview
MDL-26120 mod_forum: use correct object
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-39298 - gradebook: Added more delimiters for uploading and downloading the gradebook as a csv file.

New delimiters added: colon, semicolon
MDL-39192 mod_forum: do not need to check the posting threshold when editing a post
MDL-39355 JavaScript: Correct zIndex for tooltip
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-38440 WebService get_contents doesn't return the full text of labels
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-36024 enrol: enable grade recovery for all enrol plugins