Customize the path that the user is directed to after accepting the T&C

After the user accepted the T&C they are redirected to the user profile page. This patch allows you to customize where the user is directed to after accepting the T&C.

This patch adds an extra configuration option to the Legal admin page, a textbox of the url that the user should be redirected to. Currently it defaults to 'user' which is the same action that legal currently uses.