Whether or not the user visits the User Portal is optional: the user
could choose not to, or the Captive Portal may not provide one. Clarify
that the case presented in the component diagram is the one where the
User Portal is present, and where the user chooses to visit it.
Whether or not the user visits the User Portal is optional: the user could choose not to, or the Captive Portal may not provide one. Clarify that the case presented in the component diagram is the one where the User Portal is present, and where the user chooses to visit it.
Fixes #94