If a user signing up for a new account is the primary contact for an existing calendar, they are automatically given admin access to that calendar. So when the user logs into their account for the first time, the calendar will already be on their dashboard (no need to add the calendar link separately).
Fixed the Settings > Notifications dialog for account-based users so it no longer contains the link field.
Fixed an issue with the process of adding a user with an existing account to an organization.
A nice usability improvement: The Settings > Sharing view now displays much nicer on small screens, which will be helpful for admins who need to manage access on a mobile browser.