Fixed set_cookie max-age parsing

Max-age is expected to be in seconds and thus cannot be parsed by _since_epoch.
Expire attribute is calculated from now() and max-age
Update request.py
Merge pull request #136 from mdipierro/master

Update request.py. Take care of the possibility no receiver_addrs are defined.
Merge pull request #123 from tpazderka/cookie_expire_fix

Fixed set_cookie max-age parsing
Endpoint index when given must be an integer but stored as a character.
Editorial
Allow kwargs to percolate down through calls. Mark static methods as such.
Corrected documentation.
Merge branch 'master' of github.com:rohe/pysaml2
Created service_conf.py.example and started on using endpoint indexes
Merge remote-tracking branch 'upstream/master'
Removed endpoint index