handle failed download
Merge pull request #321 from dwrensha/download-error

don't crash on failed download
work in progress permissions rework
bug fixes and client understands to 'user' message
button to generate admin account when it does not exist
users can login, logout, edit username/password
show admins list of users in settings
admins can update permissions for users
roadmap update and other README cleanups
admins can delete users