Fix HTML, format

Throw error if modernizr feature detects not in build

Ref:
#71
#72

Add SVG <title> to polyfill for accessibility

Fix sizing of img tags with padding

Fix bug with missing padding properties with background images

Fix bug with padding on img tag

Add Firefox 35+ support, normalize cross-browser rendering

Fix bug with `display: none` on parents

Add support for programmatic toggling of grayscale

Fix image size with resized img tag and grayscale-fade in polyfill