Update a.download.html

Changed the downloadFile function to reflect API changes. Uses new
Blob() rather than BlobBuilder
submodule update
Merge pull request #4 from wyattpearsall/patch-1

Update a.download.html
Adding mimetype
Merge pull request #6 from arv/de-webkit-ify

Make ShadowDOM visualizer work better with non WebKit implementations
Add ShadowDOM as a git submodule