MDL-38102 lib: Check for null return value from password_hash function call
MDL-38555 forms: Prevent same data submission multiple times.

This disables Submit button when the form has been submitted to
prevent consequent submissions before the page has been loaded.
MDL-37966 Assignment: put upgraded modules where the originals were
MDL-38545 Reports: PHP Strict Standards error in graph.php
MDL-38480_m Fix for messy usage of language strings in block course overview
MDL-26120 mod_forum: use correct object
MDL-32898 Final deprecation of moodle_strtolower()
 MDL-34508 Formslib: Removed deprecated setHelpButton() from editor.php and hidden.php
MDL-33379 course: Removed deprecated move_section() from course/lib.php
MDL-30940 form: Mutiple select work correctly without any selection
MDL-35666 remove uninstall protocol option
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-39166 auth_ldap Add triggers for user created/updated events.
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