Hand RepozeWho1AuthenticationPolicy.remember kwargs to repoze.who #1249

Documentation for pyramid.security.remember supports keyword arguments
to hand over to the authentication policy. However, when using
RepozeWho1AuthenticationPolicy, all of the kw were dropped in remember.

It is my understanding that with repoze.who, additional configuration
parameters shall be stored in the identity dictionary. In our case,
setting the max_age parameter to the authtkt identifier, would be done
using an identity {'repoze.who.userid':principal, 'max_age': 23}.

It seems sensible just to hand over kw through the identity dictionary
and all users to specify max_age or other parameters such as userdata.
Merge pull request #1254 from rbu/repozewho1-remember-kwargs

Hand RepozeWho1AuthenticationPolicy.remember kwargs to repoze.who (master) #1249