Omit image/gif from video tags on history list

Fixes #272
Add preview to UI before calculating hash

Closes #286
Fix autoplay on loop toggle in Chrome

Fixes #280
Dim loop icon when not looping

Closes #294
Change mouse hiding mechanics on video player

Closes #285
Load history details one page at a time

Closes #274
Merge branch 'master' of github.com:MediaCrush/MediaCrush