PEP 3105 changed `print` from a statement to a function. In order to use
`print` with Python 3, all references need to be updated to a function.
Python 2, however, raises a `SyntaxError` when treating `print` as a
function. Importing `print_function` from __future__ allows `print` as a
function on all versions of Python greater than or equal to 2.6.

In b0bc25e I turned the print statement into the print function. Upon
further thought, print isn't needed at all because the exception that is
raised immediately after serves the same purpose.

In order to support newer versions of Python, the old syntax needs to be
replaced. Sorry Python 2.5.

`urlparse` has moved. Python 3 moved it to `urllib.parse`. A try/except
can be used to handle supporting both Python 2 and 3. This also changes
(and simplifies) how to get `parse_qs`.

Since bed739f killed supported for Python 2.5, the old `sha` import can
be removed, using only the newer import instead.