added login dropdown to nav, posts to forum login
Integrated IPBWI, basic login/logout seems to work

- Logout currently redirects to forum homepage; have to create custom logout page and redirect to referer
- Still don't understand auth_key for login, but may have found clues for how to generate one (using ips_wrapper in IPBWI)
Created custom signin/signout pages

Created a new layout and view for redirecting users with a message -- identical to default IPB redirect.
Created router pages for signing in and signing out users and offering them helpful messages.
No longer have to worry about auth_key.