Remove old Powered By OS and login buttons.  #1694

#1694

Duplicate Powered By OS and Login buttons were appearing on pages.  

Remove the old powered by OS and admin login buttons from the os_public, os_sitewide, os_sitewide_front and os_users contexts.  

After removing the old button and logo, there was still an issue with the login button appearing on pages it shouldn't, like the user login screen (redundant to have it there), so I removed that button from the user, private_site and user/password pages.