If executing an internal task fails, a new variant of `hyper::Error` is returned to the user, with improved messaging. If a non-critical task fails to spawn, it no longer panics, instead just logging a warning. Closes #1566
If executing an internal task fails, a new variant of `hyper::Error` is returned to the user, with improved messaging. If a non-critical task fails to spawn, it no longer panics, instead just logging a warning. Closes #1566