Loading of /etc/bash_completion
gpg-agent daemon setup and session sharing
ssh-agent daemon setup and session sharing
{gpg,ssh}-agent and completion contributions

I did develop all scripts in the previous commits as part of my employment
with LoVullo; these, however, are derived from my personal configuration,
and so I contribute them here separately.

These are thus signed with my personal GPG key, as is standard with my
commits.