Merge branch 'rv/sendemail-tocmd-in-config-and-completion'

Teach "sendemail.tocmd" to places that know about "sendemail.to", like documentation and shell completion (in contrib/). * rv/sendemail-tocmd-in-config-and-completion: completion: add git config sendemail.tocmd Documentation/config: add sendemail.tocmd to list preceding "See git-send-email(1)"