freemount-server:  Pass fd to send_response()
freemount-server:  request::file_path -> path
freemount-server:  Move request to its own unit
freemount-server:  Define request constructor
freemount-server:  Add session unit
freemountd:  Create a session
freemount-server:  Use sessions for context
freemount-server:  Use session's send fd
freemount-server:  Use session's root and cwd
freemount-server:  Axe freemount::root()
Merge branch 'sessions'