If inline SVGs are supported, img tags such as <img src="foo.svg"> are replaced with the inline contents of foo.svg.
If inline SVGs are NOT supported but SVGs ARE, then the img tag will be left as it is.
If neither SVGs NOR inline SVGs are supported, a PNG will be loaded in its place.
The SVGs and PNG equivalents must have the same path and name (except for the file extension).
Due to the same-origin policy you may have problems using this with local
See example.html for usage. There's not a lot to it.
Includes SVG and InlineSVG checks from Modernizr.