Support for SSL in wsgi.Server

SSL are entirely optional. Support for SSL as well using code from glance. We
have some new options for configuring the SSL support. There are tests for
accessing a sample app w/o ipv6 or ssl, one with just ssl and one with
ipv6 and ssl

Fixes LP# 1101342

DocImpact

Change-Id: I824acef4130d27828dcf199736b3ca668d6202d7