This is the first in a series of changes to improve type safety and

enhance tests for the hosting services suite. We begin with Unfuddle.
This change updates the Unfuddle test suite to always return byte

strings for payloads and to check for byte results. We no longer spy on

_http_get(), but rather on http_request(), which will be wrapped in

an upcoming change to check result types.
When checking the results of the spies, we now check all arguments

passed to http_request(), rather than just checking if it was called.

This allows us to ensure we're passing exactly what we expect in the

calls, and to check for type safety (on Python 3) at the same time.
Docstrings have been updated to better mention function names, helping

match other test suites, and docstrings for helper functions have been

added as well.

Unit tests pass. This has also been tested against Python 3 on the

Review Board 4.0 branch, in combination with other changes.