Alright good news; the gap remover
is fully functional now; the only drawback
*kinda* is the user has to put the image
they want gapless in a specific folder
with a specific filename because of
javascript / website security reasons;
I'm unable to bypass otherwise don't mind
writing a client-side application if requested.

Anyways here it is so far:

Here are the complete results:

The SpriteSheet with Gaps:



The SpriteSheet without Gaps:




This functionality works by crop copying 
into place rather then removing transparency.