* Make Users._login and session.authenticate always raise AccessDenied
on authentication failure instead of only sometimes (cf
Session.authenticate calling security.check() which raises and not
catching the exception)
* Alter AccessDenied such that it's possible to add a custom access
message, for use with login rate limiting instead of smuggling the
information via the session
* Alter the RPC endpoints to catch and convert AccessDenied back to
a boolean sentinel
Xavier Morel
aac21e4125