allow empty defaults for command tokens
¯\_(ツ)_/¯
Merge pull request #577 from piavlo/feature/empty-client-attributes2

allow empty defaults for command tokens
exited?() can let nil exit statuses through
extension post_init() hook, within event loop
Merge pull request #578 from portertech/extension_post_init

extension post_init() hook, within event loop
Merge pull request #579 from portertech/nil_exitstatus

exited?() can let nil exit statuses through