Sets Tweetdeck back to using stars for favorites.
NOTE: SCRIPT IS BROKEN AS OF SEPTEMBER 2016.
Tweetdeck has done exactly as stated at the bottom; the CSS no longer uses the 'hearty' class to choose sprite sheets, and instead uses the hearty sprite sheet as default; the solution will most likely be a modification of CSS after scripts have finished loading.
Old Description:
Tweetdeck accomplishes the new (and loathed) heart-shaped Favorite icon via a CSS rule that acts on the 'hearty' class; which they then (via script) apply to the body element; however, the old star-based favorite rule still exists in the CSS.
This script sets a MutationObserver to watch for that change, and then alters the class of the body element so that it is no longer 'hearty', but 'starry' (which has no special meaning in the Tweetdeck CSS).
Please note that Tweetdeck may abandon the class-based heart rule by altering the CSS to always use the 2015 sprite sheet, at which point this script will no longer help.
