add support for HTTPS
add support for HTTPS

Modify HTTP to use delegation instead of inheritance.  The
_connection_class attribute of the class defines what class to
delegate to.  The HTTPS class is a subclass of HTTP that redefines
_connection_class.

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator