atto_accessibilityhelper
Fix final argument to Handlebars
atto_table
editor_atto-menu
tidy up build
tidy up files
MDL-44164 Rewrote equation editor
MDL-44460 Atto: Build an undo/redo stack for all browsers.

Conflicts:
	lib/editor/atto/plugins/undo/yui/build/moodle-atto_undo-button/moodle-atto_undo-button-min.js
mostly docs
Tidy up of documentation
More docs'