[MERGE] Workaround SSLFile wrong readline prototype and fix bogus tests

[Ian Clatworthy]

Vincent Ladeuil wrote:

> It turns out httplib.SSLFile.readline didn't take a 'size'
> parameter as it should, bad SSLFile.

> The fix itself was pretty simple and John proposed it very
> quickly this week-end (thanks).

I was hoping someone more familiar with this bit of the system
would get to review this earlier today. The fix is pretty
obviously correct though given the analysis done, so ...

bb:approve

>>From there I started a bit of whack-a-mole game with the
> read_bundle tests that had very subtle bugs.
> 
> I ended up fixing them and deprecating read_bundle_from_url in
> the process (see patch for detailed explanations or ask questions
> during the review if needed).

I don't fully understand why these changes needed to be in the same
patch as the fix for the core issue? I would have preferred
reviewing just the fix as I think it needs to land before 1.12rc
goes out (in a few hours). Anyhow, these latter changes seem OK to
me as well.

Ian C.