Have `static_file` set the content type about itty

[defnull]

Guessing a mimetype is actually very easy.
(copy&paste from Bottle send_file)

import mimetypes
def send_file(filename, ..., guessmime = True, mimetype = None):
    ....
    if guessmime and not mimetype:
        mimetype = mimetypes.guess_type(filename)[0]
    if not mimetype: mimetype = 'text/plain'
    ....

But be careful: The python mimetypes module is not completely thread save. It must be initialized in the main thread. # Python Issue #5853

[defunkt]

itty already includes guessing content_type: http://github.com/toastdriven/itty/blob/master/itty.py#L262-275

My patch merely calls that method for you in static_file.

[toastdriven]

Again, the link doesn't seem to work for me. Help?

[defunkt]

Link should work now, sorry about that!

[toastdriven]

Fixed in SHA: dde698a