StaticFileHandler with range request support

[kzahel]

I wrote a neat extension to the static file handler so that it can
stream pieces of very large files. I don't understand the "If-Range"
header (used for caching ranges?)

This enables tornado to serve large mp4 h264 files to web browsers in
a way that enables seeking (just like youtube+html5)

I just thought I would share and see if anyone is interested in such a
feature.

https://github.com/kzahel/tornado/blob/master/tornado/web.py#L1466

[Ben Darnell]

Thanks, this does look useful. Could you put together a pull request
to separate your StaticFileHandler changes from the other changes in
your branch?

-Ben