Adding 'unsubscribed_from_emails' to the Users object.
Fixing User.all() to return all users, not just the first page
Adding support for per_page, page, tag_id, and tag_name.
Also adding unsubscribed_from_emails attribute to User.

Thanks https://github.com/sdorazio
Merged pull request from @sdorazio which fixes the ``User.all``
method to return all users and adds ``unsubscribed_from_emails``
attribute to ``User``.

Removed change to ``User.all`` that added named parameters.