MDL-45410 Merge English strings from the en_fix language pack
MDL-43312 TinyMCE: Version bump to 3.5.10. Remove all the hacks.

I retested the old bugs that required custom hacks to tinymce and could not reproduce them,
so I have not reimplemented the hacks.
MDL-45282 core_user: fixed up some oddities in the bulk user messaging screen
MDL-43119 Add valid until dates for tokens created by login/token.php

3 months were decided
MDL-45126 do not allow guests see name and summary of hidden course
Merge branch 'MDL-45410-en_fix-26' of git://github.com/mudrd8mz/moodle into MOODLE_26_STABLE
MDL-44750 Assign: Do not reveal student identities to screen readers
Merge branch 'MDL-45282_message_26' of git://github.com/andyjdavis/moodle into MOODLE_26_STABLE
MDL-45304 events: Triggering event course module update actions.
Merge branch 'MDL-45304-26' of git://github.com/lameze/moodle into MOODLE_26_STABLE
Merge branch 'MDL-43312-26' of git://github.com/damyon/moodle into MOODLE_26_STABLE
MDL-43312 tinymce: bump plugin version
MDL-45414 wiki: blank image for page index icons