Rename the admin widget classes.
Review Request #10414 — Created Feb. 18, 2019 and submitted — Latest diff uploaded
This change renames the admin widget classes to conform to our new
standard for CSS, and reorganizes a lot of the CSS to match. There's
only one small visual change, switching the background of the "Add Small
Widgets" button to be white to match the appearance of the "Add Large
Widgets" button.
Verified the appearance of the admin dashboard.