Correctly assign class to fallbackImg object

I guess I used the wrong attribute last time. should be className and not class.
Correctly assign class to fallbackImg object

Used the wrong attribute before. Should be className instead of class.
execute the callback when fadeElementTo does not need to change opacity
i.e. the element is already hidden
nix previous fade before starting this fade
fadeElementIn uses default value of 1
Merge pull request #1890 from andytuba/1889

fix hover callback issues
fadeElementIn/Out shows/hides
Merge pull request #1882 from markekraus/patch-5

Imgur and Gifyoutube fallback Image Alignment Redux
utils: Fix indentation