add a form to add a client
possibility to delete a client
remove useless info in model
display client secret
first draft of OAuth2 step 1
redirect to previous page if controller is oauth2
fix redirect
redirect user only if a 403 error was thrown
implement OAuth2 access_token
fix 404 error
delete tokens and codes with their OAuth2 client
redirect user even if controller is not oauth2
fix var conflict
fix error and remove description
add scopes

scopes can be "user", "app", "database", currently with RW access
move code to prevent a bug where requestURI is not defined
add an API on /api/user
do not disclose some critical info
Merge branch 'oauth2'