Reimplement SSL serving with Python stdlib's ssl module.

SSL via CherryPy would fail on recent GNU userlands thusly:

error: (56, 'SSL read: error:1408F10B:SSL routines:SSL3_GET_RECORD:wrong version number, errno 0')

Reported in #180 as well as for a while now by travis.
Merge pull request #189 from p-push/ssl-stdlib

Reimplement SSL serving with Python stdlib's ssl module.