MDL-41208 import YUI 3.12.0 with @VERSION@ fix for simpleyui
MDL-41128 assign: Add feedback_pdf plugin to core.
MDL-38171 assign: Work in progress on pdf edit plugin

This is heavily based on the uploadpdf submission/feedback plugins
from Davo Smith.
MDL-38171: split colour into fgcolour and bgcolour for comments
MDL-38171 editpdf: Javascript for saving changes

Remaining work is to add the saveallpages handler to ajax.php and then generate a new downloadable pdf.
MDL-38171 editpdf: Saving and loading comments is working.
MDL-38171 editpdf: Downloadable PDF generation is working.

Plans are to put a filemanager in the grade form so generated pdfs can be deleted, renamed etc.
MDL-41273 editpdf: Correct offsets when scrolling

The comments were incorrectly positioned when the page was scrolled.
MDL-41273 editpdf: No html in comments

Change the contenteditable div to a textarea.
MDL-38171 editpdf: Remove bgcolour - we only need one.
MDL-41273 editpdf: Improvements to comment tool

Make the pdf and online comments look the same (e.g. widths).
MDL-41275 editpdf: Show a link to download/delete

Add a link to the grading form to download/delete the generated pdf.
Also only allow one generated file per student attempt.
MDL-41133 editpdf: Remove unused icons
MDL-38171 editpdf: Fix styles for grade form elements

Make the launch button a real button and add style
rules for hidden class.
MDL-41273 editpdf: Add comments with single click

Also:
Fix funky behaviour when clicking dave while in an empty comment.
MDL-41273 editpdf: Fix focus jumping on delete comment

When an empty comment is blurred it is deleted - this was redrawing
the entire page - which caused the focus to shift. So if you created
an empty comment - then clicked in a real comment, the focus would shift
to a different comment. I fixed this by not redrawing the entire page -
only removing the drawable related to the comment.
MDL-41541 fix ghostcript path test
MDL-41274 PDF feedback: enable colour and tool chooser menus
MDL-41277 add rectanlge/oval/line tool to pdf feedback generator
MDL-41279 Edit PDF: Add support for pen tool