Based on suggestions from <ahelsing@bbn.com>.

This gives us a way to always CC a particular address (note that
this is different from archivemail, which makes a separate message)

A closer inspection of the 'fedora' case that I had been using revealed
that a few changes needed to be made for the CentOS 6 environment.  This
is loosely based on the fedora15 case, but stripped down and cleaned up
some.

Leigh B Stoller authored Dec 05, 2013 and Gary Wong committed Jan 08, 2014

This was a pointless path to follow since every browser is
different in how/when/why it does the window unload event, so
in fact I will have to hack shellinboxd to timeout out after a
reasonable amount of time.

This is a drawback of not using real web sockets; there is no
way for the backend to know when the browser window is gone.