Update parents relative path.
Some modifications on portal.core : 
-Move PortalUserAuthentication to API package to be usable externaly.
-PortalUserAuthentication have now two constructors
-Modify ILoginManager to return IAuthentication on login() call and add
a test isLogged() method.
Some comments in xml config files.
Minimal css modification.
New Osgi Portal App (OPA) : opa-login wich allo user to login.