added option to disable background image gallery animation (fade effect)
background gallery autoplay animation option fix
added 3 more positions for banners
image generation for 2x displays, srcset for gallery images, imagefill.js for unsupported devices
1x image added to srcset to prevent 2x loading
2x image support for logo and banners
warning helper text updated for 2x image upload
version upgrade, readme update
master changes merged - retina ready