Don't use SESSION_COOKIE_PARAM_DOMAIN

In my testing enviro SESSION_COOKIE_PARAM_DOMAIN was not defined, so my
browser received this header:

Set-Cookie: ccmAuthUserHash=...; expires=...; path=/; domain=SESSION_COOKIE_PARAM_DOMAIN

Clearly a problem...
Use SESSION_COOKIE_PARAM for remember user cookie

Also, let's use USER_FOREVER_COOKIE_LIFETIME instead of the hardcoded
duration of 1209600
Merge pull request #171 from mlocati/fix-rememberuser-cookie

Don't use SESSION_COOKIE_PARAM_DOMAIN