Fix Pagination Helpers to point to use URL constants.
Styling updates: hovering over logo no longer adds BG, notes anywhere
Update documentation to reflect the current Alpha state

* Remove basic information on the home page that does not apply for
  the current version of API V2
  * Add note about naming client applications
* Remove unsupported authentication methods, for now we're keeping the
  token login pattern from API V1
* Add warning notice that the API is still in Alpha testing to every
  page