Issue
Short text alternative - The recent files repository refresh icon is missing alternative text. The fp-vb-icons, fp-vb-details, fp-vb-tree icons are missing alternative text or titles.

Add..., create folder and the file icons all need empty alt text (alt="").

All repository icons to the left of the repository name need empty alt text.

Private files repository manage and Private files folder icon need empty alt text

Standard Level
WCAG 2 1.1.1 (A) http://www.w3.org/WAI/WCAG20/quickref/#qr-text-equiv-all

Impact
Critical

Example Link
http://demo.moodle.net/mod/assign/view.php?id=1775&action=editsubmission

Test Steps

1. Login as student
2. Navigate to course
3. Asswignment must exist
4. Click on Assignment
5. Click add submission button
6. View each of the icons in the file picker
7. Click the add button and view each icon in each repository.