MDL-39980 essay attempt-on-last. Handle the no-files case.

This slighly changes the format for the way answers are stroed in the DB
in the case where there is some HTML content, but no files. This should
not cause any problems.
MDL-39474 fix incorrect bitwise ops when setting $CFG->debugdeveloper
MDL-39474 add set_debugging() tests
MDL-30839 Fixing extra line breaks in error msg
MDL-41125 forum: Missing include of repository lib
Merge branch 'MDL-39980' of git://github.com/timhunt/moodle
Merge branch 'MDL-30839-master' of git://github.com/phalacee/moodle
Merge branch 'MDL-41125-master' of git://github.com/FMCorz/moodle
Merge branch 'debugdeveloperbitwisemess' of git://github.com/skodak/moodle
MDL-41196 phpmailer: fixed unit test detection
MDL-30839 Accessibility - Focusing on error on submit
Merge branch 'MDL-30839-master' of git://github.com/phalacee/moodle
Merge branch 'wip-MDL-41196-m26' of git://github.com/samhemelryk/moodle
Revert "MDL-40931 useragent: separated user agent functionality into a lib"

This reverts commit af62237d0e6e27df868d50848f7098f57c103f86.
This reverts commit 87a4194fdcd322d4aee5a6207b55a8da0864da94.
This reverts commit b2c66eb60c01805f26cc791966f05be52af7b406.

Conflicts:

	version.php
Revert "MDL-35380 SCORM: improve check for imsmanifest file and consolidate into a single function."

This reverts commit 492407e9f734989782e6380c381cfa14a09b1b26.
MDL-36002 dragdrop: Implement keyboard dragdrop for blocks

This is for the NEW block drag and drop code - not the other one :)
All it does it add proper drag handles.
Revert "MDL-36044 - Delete Icon ("X") blocks Score numbers, when in RTL mode (mod/assign , Rubrics editor)"

This reverts commit 42fabe1e87da7eb9ca5e5f3414402a357babcc3e.
weekly release 2.6dev