New: navigation buttons for full expanded images
Fix buttons display
Navigate images cyclically
Ignore hidden posts and threads
Get prev/next images lazily
Rename 'imagesData' to 'images' and make it an array
Remove duplicate code
Remove extra file inputs on krautchan when post is sent. Refs #552
Remove file input on krautchan instead of clearing
Replace unsafeWindow in 3bd304d and a694c39
Fix #552 part 2
Fix other form elements in #552 part 2