MDL-36804 mod_assign - allow students to resubmit work and display a submission + grading history
Merge branch 'MDL-36804_assign_resubmission' of git://github.com/davosmith/moodle into MDL-36804-master

Conflicts:
	mod/assign/db/install.xml
	mod/assign/locallib.php
	mod/assign/mod_form.php
	mod/assign/styles.css
MDL-36804: Cleanup DB changes and rollback all other code.

I'll be porting the functionality across to this clean branch piece by piece with unit tests
for each part.

Unit tests are currently passing with the DB changes.
MDL-33946 course dndupload - fixes to dialog when dragging text

Radio buttons have unique IDs, matching the label IDs
'What do you want to call this text' input moved down and disabled when 'label' selected
'Add page here' changed to 'Add text here'
Merge branch 'MDL-33946_label_dndupload_text' of git://github.com/davosmith/moodle
Merge branch 'master' of git://git.moodle.org/integration into MDL-36804-master
Work in progress