Replace webDiplomacy with BitDip

Changed text references to webDiplomacy
Added authorized session variable

$_SESSION['authorized'] is only set after successful login, not just
cookie. This will have to be set in order to access usercp for things
like pw change.
Moved session_start() to header

In order to make greater use of session variables.
Created $_SESSION['authorized']

$_SESSION['authorized'] is set only when a user is signing in to their
account. It is not set when a user is authorized by cookie.

usercp is now only accessible after successful sign-in. This increases
the security of things like pw or email changes.
Merge remote-tracking branch 'origin/BitDip-registration'