Crude check for a base64 string before decoding a user login.  If not base64, then return an empty string.  attempting to decode a non-base64 string returns non ASCII characters.
update README instructions
Remove "Public Subscribers" tab and functionality.  Fix logic that allows admins to edit a user's subscriptions individually.  Change header of Subscribers section to be "User Subscriptions" instead of "Registered Users"
Merge branch 'develop' into staging